A167272 Row sums of triangle A167271.

1, 2, 2, 4, 2, 6, 2, 9, 3, 8, 2, 19, 2, 10, 4, 25, 2, 23, 2, 34, 4, 14, 2, 78, 3, 16, 4, 53, 2, 76, 2, 98, 4, 20, 4, 161, 2, 22, 4, 215, 2, 146, 2, 103, 6, 26, 2, 493, 3, 155, 4, 134, 2, 252, 4, 481, 4, 32, 2, 919, 2, 34, 6, 682, 4, 402, 2, 208, 4, 832, 2, 1862, 2, 40, 6

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..1000

Formula

a(n) = A000005(n) for odd n. - Andrew Howroyd, Sep 20 2025

Example

a(6) = 6 = (1 + 3 + 1 + 0 + 0 + 1).

Prog

(PARI) a(n) = sumdiv(n, d, if(d%2, 1, binomial(n/d + d/2 - 1, d/2))) \\ Andrew Howroyd, Sep 20 2025

Crossrefs

Cf. A000005, A167271.

Sequence in context: A143112 A286472 A279690 * A090624 A304407 A099735

Adjacent sequences: A167269 A167270 A167271 * A167273 A167274 A167275

Keyword

nonn

Author

Gary W. Adamson & Mats Granvik, Oct 31 2009

Extensions

Offset changed, a(15) corrected and a(32) onwards from Andrew Howroyd, Sep 20 2025

Status

approved