A371481 - OEIS

A371481

Expansion of e.g.f. Product_{k>=1} (1 + x^k/k!)^(k*(k+1)/2).

1, 1, 3, 15, 52, 335, 2031, 12880, 102614, 802443, 6956995, 64721756, 633754320, 6551212057, 71375943289, 820250162880, 9747543483676, 121775559807881, 1580353806494781, 21246545374234378, 296590230821338520, 4280692741624646151, 63852747607056438283

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OFFSET

0,3

COMMENTS

"EGJ" (unordered, element, labeled) transform of triangular numbers.

LINKS

Table of n, a(n) for n=0..22.

C. G. Bower, Transforms (2)

MATHEMATICA

nmax = 22; CoefficientList[Series[Product[(1 + x^k/k!)^(k (k + 1)/2), {k, 1, nmax}], {x, 0, nmax}], x] Range[0, nmax]!

CROSSREFS

Cf. A000217, A007837, A028377, A032315, A032316, A371309.