OFFSET
1,1
COMMENTS
These are points at which the second differences (A376599) are zero.
Inclusive means 1 is a prime-power but not a non-prime-power. For the exclusive version, add 1 to all terms.
LINKS
EXAMPLE
The non-prime-powers inclusive are (A024619):
6, 10, 12, 14, 15, 18, 20, 21, 22, 24, 26, 28, 30, 33, 34, 35, 36, 38, 39, 40, ...
with first differences (A375735):
4, 2, 2, 1, 3, 2, 1, 1, 2, 2, 2, 2, 3, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, ...
with first differences (A376599):
-2, 0, -1, 2, -1, -1, 0, 1, 0, 0, 0, 1, -2, 0, 0, 1, -1, 0, 1, 0, -1, 0, 1, 0, ...
with zeros at (A376600):
2, 7, 9, 10, 11, 14, 15, 18, 20, 22, 24, 26, 29, 30, 31, 33, 39, 41, 43, 44, ...
MATHEMATICA
Join@@Position[Differences[Select[Range[100], !(#==1||PrimePowerQ[#])&], 2], 0]
CROSSREFS
These are the zeros of A376599.
The complement is A376601.
For non-prime-powers: A375735/A375708 (first differences), A376599 (second differences), A376601 (nonzero curvature).
KEYWORD
nonn
AUTHOR
Gus Wiseman, Oct 05 2024
STATUS
approved