A137631 - OEIS

A137631

Left border of triangle A137629.

1, 2, 4, 7, 11, 18, 26, 39, 55, 79, 106, 150, 196, 267, 349, 464, 592, 781, 984, 1275, 1601, 2041, 2536, 3217, 3961, 4961, 6094, 7566, 9220, 11392, 13801, 16917, 20438, 24878, 29909, 36269, 43387, 52307, 62428, 74900, 89012, 106427, 126038, 150048, 177278, 210195, 247541, 292706

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OFFSET

1,2

LINKS

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

FORMULA

Equals A026794 * A000041 as matrices.

EXAMPLE

a(4) = 7 = (3, 1, 0, 1) dot (1, 1, 2, 3), where (3, 1, 0, 1) = row 4 of the partition triangle A026794 and (1, 1, 2, 3) = the first 4 terms of A000041.

PROG

(PARI) \\ Needs MtxA026794 defined in A026794.

seq(n) = (MtxA026794(n)*vectorv(n, i, numbpart(i-1)))~ \\ Andrew Howroyd, Sep 21 2025

CROSSREFS

Cf. A000041, A026794, A137629.

Sequence in context: A129929 A360891 A073738 * A003403 A261666 A034412

Adjacent sequences: A137628 A137629 A137630 * A137632 A137633 A137634

KEYWORD

nonn

AUTHOR

Gary W. Adamson, Jan 31 2008

EXTENSIONS

a(15) onwards from Andrew Howroyd, Sep 21 2025

STATUS

approved