A324814 Numbers n > 1 for which sigma(A156552(n)) == 2 (mod 4).

6, 14, 15, 18, 33, 35, 38, 42, 54, 58, 65, 69, 70, 75, 77, 90, 93, 102, 106, 110, 119, 130, 143, 145, 150, 162, 165, 174, 177, 185, 190, 209, 217, 221, 230, 231, 234, 242, 245, 273, 285, 287, 290, 294, 299, 305, 323, 330, 338, 350, 357, 375, 378, 390, 407, 410, 414, 434, 437, 450, 455, 465, 469, 473, 483, 493, 494, 507

Offset

1,1

Comments

Sequence A005940(1+A191217(n)), n >= 1, sorted into ascending order.

Links

Table of n, a(n) for n=1..68.

Index entries for sequences related to binary expansion of n

Index entries for sequences computed from indices in prime factorization

Index entries for sequences related to sigma(n)

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 by David A. Corneth
A324824(n) = ((n>1)&&(2==(sigma(A156552(n))%4)));
A324824(n) = (2==(A323243(n)%4)); \\ Alternatively.
for(n=1, oo, if(A324824(n), print1(n, ", ")));

Crossrefs

Cf. A000203, A005940, A191217, A324812, A324813, A324824 (characteristic function).

Sequence in context: A184998 A322561 A079010 * A015822 A023883 A230873

Adjacent sequences: A324811 A324812 A324813 * A324815 A324816 A324817

Keyword

nonn

Author

Antti Karttunen, Mar 16 2019

Status

approved