A332227 Odd numbers k such that sigma(k) is congruent to 2 modulo 8.

17, 41, 73, 89, 97, 113, 137, 153, 193, 233, 241, 257, 281, 313, 325, 337, 353, 369, 401, 409, 433, 449, 457, 521, 569, 577, 593, 601, 617, 641, 657, 673, 725, 761, 769, 801, 809, 833, 845, 857, 873, 881, 925, 929, 937, 953, 977, 1009, 1017, 1033, 1049, 1097, 1129, 1153, 1193, 1201, 1217, 1233, 1249, 1289, 1297, 1321

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..25000

Index entries for sequences related to sigma(n)

Mathematica

Select[Range[1, 1401, 2], Mod[DivisorSigma[1, #], 8]==2&] (* Harvey P. Dale, Apr 12 2021 *)

Prog

(PARI) isA332227(n) = ((n%2)&&2==(sigma(n)%8));

Crossrefs

Cf. A000203.

Subsequence of A191218 and of A332226.

Cf. A332228 (a subsequence, terms that are not prime powers).

Sequence in context: A147215 A126790 A089200 * A263011 A263012 A172280

Adjacent sequences: A332224 A332225 A332226 * A332228 A332229 A332230

Keyword

nonn

Author

Antti Karttunen, Feb 13 2020

Status

approved