A391584 Odd numbers k such that 3*k = A048720(m,k) for some m, where A048720 is carryless base-2 multiplication.

1, 3, 5, 7, 9, 15, 17, 21, 31, 33, 37, 41, 51, 63, 65, 69, 73, 81, 85, 99, 103, 115, 127, 129, 133, 137, 145, 149, 161, 165, 169, 195, 199, 207, 227, 231, 243, 255, 257, 261, 265, 273, 277, 289, 293, 297, 321, 325, 329, 337, 341, 387, 391, 399, 415, 451, 455, 463, 483, 487, 499, 511, 513, 517, 521, 529, 533, 545

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.

Prog

(PARI) A391584(n) = forstep(i=1, oo, 2, my(P3i=Pol(binary(3*i))*Mod(1, 2), P_i=Pol(binary(i))*Mod(1, 2)); if(0==lift(P3i % P_i), if(n>1, n--, return(i))));
(PARI)
up_to = 10000;
A391584list(up_to_n) = { my(v=vector(up_to_n), k=0, i = -1); while(k<#v, i += 2; my(P3i=Pol(binary(3*i))*Mod(1, 2), P_i=Pol(binary(i))*Mod(1, 2)); if(0==lift(P3i % P_i), k++; v[k] = i)); (v); };
v391584 = A391584list(up_to);
A391584(n) = v391584[n];

Crossrefs

Row 3 of A391725. Odd terms of A391585.

Cf. A048720.

Sequence in context: A006995 A163410 A329419 * A235264 A064896 A076188

Adjacent sequences: A391581 A391582 A391583 * A391585 A391586 A391587

Keyword

nonn,base

Author

Antti Karttunen, Dec 18 2025

Status

approved