login
A332812
Numbers n for which A156552(n) == 2 (mod 3).
7
3, 6, 7, 12, 13, 14, 19, 24, 26, 27, 28, 29, 35, 37, 38, 43, 48, 52, 53, 54, 56, 58, 61, 63, 65, 70, 71, 74, 75, 76, 79, 86, 89, 95, 96, 101, 104, 106, 107, 108, 112, 113, 116, 117, 122, 126, 130, 131, 139, 140, 142, 143, 145, 147, 148, 150, 151, 152, 158, 163, 165, 171, 172, 173, 175, 178, 181, 185, 190, 192, 193, 199, 202
OFFSET
1,1
COMMENTS
Contains neither squares nor twice squares.
LINKS
PROG
(PARI)
A156552(n) = {my(f = factor(n), p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res}; \\ From A156552
isA332812(n) = (2==(A156552(n)%3));
CROSSREFS
Positions of 2's in A329903, of -1's in A332814.
Cf. A031215 (a subsequence of prime terms).
Cf. also A332822.
Sequence in context: A004760 A186083 A093906 * A152829 A325430 A104463
KEYWORD
nonn
AUTHOR
Antti Karttunen, Feb 27 2020
STATUS
approved