A391745 Odd numbers k such that 9*k = A048720(m, k) for some m, where A048720 is carryless base-2 multiplication.

1, 3, 5, 7, 15, 17, 21, 31, 33, 35, 49, 63, 65, 67, 69, 71, 81, 85, 97, 99, 113, 127, 129, 131, 133, 135, 161, 163, 193, 195, 197, 199, 225, 227, 255, 257, 259, 261, 263, 273, 277, 321, 323, 325, 327, 337, 341, 385, 387, 389, 391, 449, 451, 453, 455, 511, 513, 515, 517, 519, 529, 533, 545, 547, 561, 641, 643, 645

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

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

{Odd k such that A280500(9*k, k) = m for some m > 0}.

Prog

(PARI) is_A391745(k) = ((k%2) && (0==lift(Pol(binary(9*k)*Mod(1, 2)) % Pol(binary(k))*Mod(1, 2))));

Crossrefs

Row 9 of A391725. Odd terms of A391744.

Cf. A048720, A280500.

Cf. also A391584, A391741, A391743.

Sequence in context: A160690 A085494 A348441 * A356591 A029460 A277910

Adjacent sequences: A391742 A391743 A391744 * A391746 A391747 A391748

Keyword

nonn,base

Author

Antti Karttunen, Dec 21 2025

Status

approved