Each term increases by 3, making this a simple arithmetic series (multiples of 3). The next term is 15 + 3 = 18. Interviewers use this to check whether a candidate quickly identifies a constant common difference.

Each term is double the previous one — a geometric progression with a common ratio of 2. So the next term is 80 x 2 = 160. This type checks whether a candidate can distinguish multiplication-based growth from addition-based growth.

These are perfect squares of consecutive numbers: 1², 2², 3², 4², 5². The next term is 6² = 36. This tests recognition of square-number sequences, a very common interview pattern.

These are perfect cubes: 1³, 2³, 3³, 4³, 5³. The next term is 6³ = 216. Cube series are slightly trickier than squares and often appear in advanced rounds.

This is a series of prime numbers in increasing order. The next prime after 13 is 17. This checks whether the candidate recognizes prime numbers, not just arithmetic patterns.

This is the Fibonacci sequence, where each term is the sum of the two preceding terms. 8 + 13 = 21, so the next term is 21. Fibonacci-based questions are a favorite in technical and analytical interviews.

Each term decreases by 10 — a simple descending arithmetic series. The next term is 60 - 10 = 50. This tests whether candidates can handle decreasing patterns just as easily as increasing ones.

The differences between terms increase by 2 each time (3, 5, 7, 9...). Adding the next difference, 11, to 27 gives 38. This is a second-order arithmetic series where you must look at the differences of differences.

Each term doubles the previous one, a geometric series with ratio 2. The next term is 112 x 2 = 224. This reinforces the doubling pattern with slightly larger numbers to test calculation speed.

Each term follows the pattern n² + 1, for n = 1, 2, 3, 4, 5. The next term is 6² + 1 = 37. This tests whether a candidate can spot a formula-based pattern rather than just a constant difference.

The differences increase by 1 each time (1, 2, 3, 4, 5...). Adding the next difference, 6, to 16 gives 22. This is a common triangular-number-style progression.

The amount subtracted increases each time (1, 2, 3, 4, 5...). So 0 - 5 = -5 is the next term. This tests comfort with decreasing series that go into negative numbers.

These are triangular numbers, where each term adds one more than the previous addition (1, 2, 3, 4, 5...). The next term is 15 + 6 = 21. Triangular number series are a classic reasoning-test favorite.

The differences between terms increase by 5 each time (5, 10, 15, 20, 25...). Adding 25 to 56 gives 81. This checks whether a candidate can identify a consistent second-level pattern in the differences.

This is a two-interleaved series: one part goes 1, 2, 3, 4... and the other goes 10, 20, 30, 40... Since the last term shown is 30, the next term continues the first pattern: 4. Interleaved series test whether candidates can separate two hidden patterns within one sequence.

Each term is double the previous term plus 1 (3x2+1=7, 7x2+1=15, and so on). The next term is 63 x 2 + 1 = 127. This is a common multiply-and-add pattern used to test multi-step reasoning.

Each term follows n(n+1), for n = 1, 2, 3, 4, 5. The next term is 6 x 7 = 42. This series often appears disguised as a 'difference of differences' problem, since the gaps also increase steadily (4, 6, 8, 10...).

Each term is double the previous term plus 1 (5x2+1=11, 11x2+1=23, and so on). The next term is 95 x 2 + 1 = 191. This is a slightly harder variant of the multiply-and-add pattern, often used to filter strong candidates.

Each term doubles the one before it, a geometric series with ratio 2. The next term is 64 x 2 = 128. Powers-of-two series are extremely common in technical interviews since they connect to binary and computing concepts.

This is an alternating series: multiply by 3, then divide by 2, repeating. 18 x 3 = 54, so the next term is 54. Alternating operation series test whether a candidate can track two different rules applied in turn.

Each term is the previous term multiplied by the next whole number (factorials): 1!, 2!, 3!, 4!, 5!. The next term is 120 x 6 = 720 (6!). Factorial series are a favorite in campus placement tests.

From the third term onward, each term is the sum of the two preceding terms (a Fibonacci-style pattern): 4+7=11, 7+11=18, so the next term is 11+18=29. This checks whether candidates notice Fibonacci-like rules even when the starting numbers differ from the classic sequence.

Each term is double the previous term plus 1. 47 x 2 + 1 = 95, so that's the next term. This is another common multiply-and-add-1 variant, useful for testing calculation accuracy under time pressure.

Each term is double the previous term plus 2 (1x2+2=4, 4x2+2=10, and so on). The next term is 46 x 2 + 2 = 94. This variation adds a constant instead of 1, so candidates must verify the exact rule rather than assume a familiar pattern.

These are descending perfect squares: 15², 14², 13², 12², 11². The next term is 10² = 100. Descending square series test whether a candidate can recognize a pattern that isn't simply increasing.

Each term follows n² - 1, for n = 1, 2, 3, 4, 5. The next term is 6² - 1 = 35. This is a common formula-based series that looks irregular until the underlying square pattern is spotted.

Each term doubles the one before it, following powers of 2 (2⁰, 2¹, 2², 2³...). The next term is 32 x 2 = 64. Because it starts at 1, this variant sometimes confuses candidates who assume it must start differently — a good check for careful reading.

The differences between terms double each time (3, 6, 12, 24...). Adding the next difference, 48, to 52 gives 100. This tests whether a candidate can spot a geometric pattern hidden inside the differences rather than the terms themselves.

This is a Fibonacci-style series where each term is the sum of the two before it. 13 + 21 = 34, so that's the next term. This is one of the most frequently repeated patterns across aptitude and interview tests, so recognizing it quickly is a strong signal of pattern-reasoning skill.