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A375713
Indices of consecutive non-prime-powers (A361102) differing by 1. Numbers k such that the k-th and (k+1)-th non-prime-powers differ by just one.
14
5, 8, 9, 15, 16, 17, 19, 20, 23, 24, 27, 28, 30, 31, 32, 33, 36, 38, 40, 41, 44, 45, 46, 47, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 63, 64, 67, 68, 71, 72, 74, 75, 76, 77, 78, 79, 81, 82, 85, 87, 88, 89, 90, 93, 94, 95, 96, 97, 98, 99, 100, 103, 104, 105, 106
OFFSET
1,1
FORMULA
A361102(k+1) - A361102(k) = 1.
EXAMPLE
The initial non-prime-powers are 1, 6, 10, 12, 14, 15, 18, 20, 21, which first increase by one after the fifth and eighth terms.
MATHEMATICA
Join@@Position[Differences[Select[Range[100], !PrimePowerQ[#]&]], 1]
CROSSREFS
The inclusive version is a(n) - 1.
For prime-powers inclusive (A000961) we have A375734, differences A373671.
For nonprime numbers (A002808) we have A375926, differences A373403.
For prime-powers exclusive (A246655) we have A375734(n+1) + 1.
First differences are A373672.
Positions of 1's in A375708.
For non-perfect-powers we have A375740.
Prime-powers inclusive:
- terms: A000961
- differences: A057820
Non-prime-powers inclusive:
- terms: A361102
- differences: A375708
A000040 lists all of the primes, differences A001223.
A007916 lists non-perfect-powers, differences A375706.
Sequence in context: A334919 A047616 A287551 * A231065 A314576 A045221
KEYWORD
nonn
AUTHOR
Gus Wiseman, Sep 02 2024
STATUS
approved