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Sequence and series?
The next term in the series: 2, 7, 28, 63, 126, __?
The answer is 215. Could you please explain how?
2 Answers
- PuzzlingLv 73 weeks agoFavorite Answer
Let's compare your sequence to the sequence of cubes:
1^3 = 1
2^3 = 8
3^3 = 27
4^3 = 64
5^3 = 125
6^3 = 216
You sequence appears to alternate between adding 1 or subtracting 1 from the sequence of cubes:
1 + 1 = 2
8 - 1 = 7
27 + 1 = 28
64 - 1 = 63
125 + 1 = 126
216 - 1 = 215
Answer:
215
- Ian HLv 73 weeks ago
Alternate nth terms are n^3 + 1, and n^3 -1
Next term is 6^3 - 1 = 215
Puzzling found this first
