A342643 a(n) = [x^n] x * Product_{j>=0} (1 + x^(2^j) + n*x^(2^(j+1))).

0, 1, 1, 4, 1, 11, 7, 57, 1, 28, 21, 265, 13, 365, 211, 3616, 1, 69, 55, 1141, 41, 1828, 1013, 25439, 25, 1951, 1405, 41608, 813, 50519, 27931, 954305, 1, 166, 137, 5041, 109, 8363, 4447, 182638, 81, 10251, 7183, 327403, 3961, 372736, 198997, 9971521, 49, 9801

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..16384

Formula

a(2^n) = 1 for n >= 0.

Maple

b:= proc(n, i) option remember; `if`(n<2, n, (h->
      `if`(p=0, b(h, i), i*b(h, i)+b(h+1, i)))(iquo(n, 2, 'p')))
    end:
a:= n-> b(n$2):
seq(a(n), n=0..55);

Crossrefs

Cf. A002487.

Sequence in context: A183884 A135552 A181690 * A109088 A060923 A298362

Adjacent sequences: A342640 A342641 A342642 * A342644 A342645 A342646

Keyword

nonn,look

Author

Alois P. Heinz, Mar 17 2021

Status

approved