A391730 Numbers k such that A115873(k) is not of the form 2^e - 1.

13, 26, 49, 52, 57, 61, 81, 98, 104, 114, 122, 123, 161, 162, 169, 181, 193, 196, 203, 205, 208, 211, 228, 235, 241, 244, 246, 251, 253, 322, 324, 333, 337, 338, 357, 362, 386, 392, 405, 406, 410, 416, 422, 435, 449, 456, 470, 471, 482, 488, 491, 492, 502, 505, 506, 577, 643, 644, 648, 666, 674, 676, 681, 714, 723

Offset

1,1

Comments

If k is a term, then 2*k is also a term, and vice versa.

Links

Antti Karttunen, Table of n, a(n) for n = 1..12030 (terms less than 2^18)

Index entries for sequences defined by congruent products between domains N and GF(2)[X]

Index entries for sequences related to binary expansion of n.

Index entries for sequences related to carryless arithmetic.

Formula

{k | A036987(A115873(k)) == 0}.

Prog

(PARI)
A209229(n) = (n && !bitand(n, n-1));
is_A391730(n) = !A209229(1+A115873(n));

Crossrefs

Cf. A000225, A036987, A115873, A391727 (subsequence), A391731 [= A115873(a(n))], A391732 (complement).

Sequence in context: A044838 A033010 A019551 * A098961 A033897 A005029

Adjacent sequences: A391727 A391728 A391729 * A391731 A391732 A391733

Keyword

nonn,base

Author

Antti Karttunen, Dec 20 2025

Status

approved