A391741 Odd numbers k such that 5*k = A048720(m, k) for some m, where A048720 is carryless base-2 multiplication.

1, 3, 7, 9, 15, 17, 19, 25, 31, 33, 35, 49, 51, 63, 65, 67, 73, 97, 99, 127, 129, 131, 137, 145, 147, 153, 193, 195, 201, 255, 257, 259, 265, 273, 275, 281, 289, 291, 305, 307, 385, 387, 393, 401, 403, 409, 455, 511, 513, 515, 521, 529, 531, 537, 545, 547, 561, 563, 577, 579, 585, 609, 611, 769, 771, 777, 785, 787

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(5*k, k) = m for some m > 0}.

Prog

(PARI) is_A391741(k) = ((k%2) && (0==lift(Pol(binary(5*k)*Mod(1, 2)) % Pol(binary(k))*Mod(1, 2))));

Crossrefs

Row 5 of A391725. Odd terms of A391740.

Cf. A048720, A280500.

Cf. also A391584, A391743.

Sequence in context: A279617 A199919 A346303 * A178207 A210532 A110872

Adjacent sequences: A391738 A391739 A391740 * A391742 A391743 A391744

Keyword

nonn,base

Author

Antti Karttunen, Dec 21 2025

Status

approved