A324727 Odd numbers such that 2n is equal to A318466(n), bitor(2*n,sigma(n)), where bitor is A003986.

3, 7, 15, 21, 31, 55, 57, 63, 93, 105, 111, 127, 171, 189, 201, 213, 215, 217, 231, 237, 249, 253, 255, 315, 351, 357, 363, 369, 381, 393, 447, 465, 469, 473, 483, 489, 497, 501, 511, 651, 705, 747, 759, 789, 813, 831, 833, 879, 889, 895, 917, 959, 987, 989, 1001, 1015, 1023, 1155, 1365, 1377, 1407, 1467, 1491, 1503, 1505, 1515, 1533, 1595

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..20000

Index entries for sequences related to binary expansion of n

Index entries for sequences where any odd perfect numbers must occur

Index entries for sequences related to sigma(n)

Mathematica

Select[Range[1, 2000, 2], 2*# == BitOr[2*#, DivisorSigma[1, #]] &] (* Paolo Xausa, Mar 11 2024 *)

Prog

(PARI) for(n=1, oo, if((n%2)&&((2*n)==bitor(2*n, sigma(n))), print1(n, ", ")));

Crossrefs

Odd terms of A324726.

Cf. A000203, A003986, A318466, A324647, A324718, A324719.

Sequence in context: A175544 A373941 A139208 * A320026 A146435 A046932

Adjacent sequences: A324724 A324725 A324726 * A324728 A324729 A324730

Keyword

nonn,look

Author

Antti Karttunen, Mar 15 2019

Status

approved