A157031 - OEIS

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A157031

Triangle A054521 * A157019, where A054521 = an infinite lower triangular matrix and A157019 = a vector [1, 2, 2, 4, 2, 8, 2, 10, 8, ...].

1, 1, 3, 3, 9, 3, 19, 7, 21, 13, 51, 7, 87, 17, 39, 51, 175, 11, 239, 21, 169, 111, 415, 15, 489, 185, 313, 219, 1017, 15, 1413, 283, 763, 415, 981, 513, 3057, 839, 1259, 497, 4425, 93, 5605, 893, 1311, 2259, 7505, 521, 8267, 1429, 5473, 3311, 13821, 1449, 11135, 4095

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

OFFSET

1,3

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

a(4) = 3 = (1, 0, 1, 0) dot (1, 2, 2, 4) = (1 + 0 + 2 + 0), where (1, 0, 1, 0) equals row 4 of triangle A054521.

MAPLE

A157031 := proc(n)

add(A054521(n, k)*A157019(k), k=1..n) ;

end proc: # R. J. Mathar, Jul 21 2015

CROSSREFS