A080978 - OEIS

A080978

a(n) = 2*A006046(n) + 1.

1, 3, 7, 11, 19, 23, 31, 39, 55, 59, 67, 75, 91, 99, 115, 131, 163, 167, 175, 183, 199, 207, 223, 239, 271, 279, 295, 311, 343, 359, 391, 423, 487, 491, 499, 507, 523, 531, 547, 563, 595, 603, 619, 635, 667, 683, 715, 747, 811, 819, 835, 851, 883, 899, 931, 963

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

The number of edges in A080973-trees.

Conjectured partial sums of A131136. - Sean A. Irvine, Jun 25 2022

LINKS

Michael De Vlieger, Table of n, a(n) for n = 0..10000

Hsien-Kuei Hwang, Svante Janson, and Tsung-Hsi Tsai, Identities and periodic oscillations of divide-and-conquer recurrences splitting at half, arXiv:2210.10968 [cs.DS], 2022, pp. 6, 30.

MATHEMATICA

Map[2 # + 1 &, {0}~Join~Accumulate@ Map[Count[#, _?OddQ] &, Table[Binomial[n, k], {n, 0, 54}, {k, 0, n}]]] (* Michael De Vlieger, Oct 30 2022 *)

CROSSREFS