A129834 (k-1)/2 where k runs over odd terms of A001372.

0, 0, 1, 3, 9, 23, 171, 475, 1307, 10245, 28951, 233099, 664496, 5442024, 3109434694, 218785948496

Offset: 1

Author

Roger L. Bagula, May 21 2007

Keywords

• nonn
• less

Comments

Original definition: Suggested by A001372 as odd numbers to 130.

Links

• F. Hivert, J.-C. Novelli and J.-Y. Thibon, Commutative combinatorial Hopf algebras, arXiv:math/0605262 [math.CO], 2006.

Crossrefs

Cf. A001372.

Programs

Mathematica

A001372 = {1, 1, 3, 7, 19, 47, 130, 343, 951, 2615, 7318, 20491, 57903, 163898, 466199, 1328993, 3799624, 10884049, 31241170, 89814958, 258604642, 745568756, 2152118306, 6218869389, 17988233052, 52078309200, 150899223268, 437571896993 }; Flatten[Table[If[IntegerQ[(A001372[[n]] - 1)/2], (A001372[[n]] - 1)/2, {}], { n, 1.Length[A001372]}]]

Formula

A129834 = { (A001372(n)-1)/2 ; n such that A001372(n) is odd }. - Corrected by M. F. Hasler, Nov 05 2014

Extensions

New definition and minor edits by M. F. Hasler, Nov 05 2014