A036655 Numbers d_n used in recurrence for series-parallel numbers.

1, 2, 2, 6, 2, 18, 2, 46, 14, 126, 2, 454, 2, 1266, 134, 4222, 2, 14202, 2, 46406, 1274, 155502, 2, 531790, 122, 1792810, 13802, 6126334, 2, 21032794, 2, 72121854, 155510, 248396798, 1382, 857944150, 2, 2964896882, 1792818, 10269600622

Offset

0,2

References

J. Riordan, An Introduction to Combinatorial Analysis, foot of p. 141.

Links

Table of n, a(n) for n=0..39.

Formula

G.f.: S'*(1-S)/(1+S), where S = g.f. for A000084.

Crossrefs

Sequence in context: A102628 A211776 A325248 * A319356 A098792 A061057

Adjacent sequences: A036652 A036653 A036654 * A036656 A036657 A036658

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved