A089835 a(n) = (A000108(n)^2)*(n+1)!.

1, 2, 24, 600, 23520, 1270080, 87816960, 7420533120, 742053312000, 85781362867200, 11260753452748800, 1655330757554073600, 269436914075724595200, 48113734656379392000000

Offset

0,2

Comments

This sequence gives the total number of non-recursive "clauses" of n opening nodes, used in the construction of A089840.

Links

Table of n, a(n) for n=0..13.

Formula

a(n) = A001246(n)*A000142(n+1) = A001813(n)*A000108(n).

Prog

(MIT/GNU Scheme) (define (A089835 n) (* (A000108 n) (A000108 n) (A000142 (1+ n))))

Crossrefs

INVERTi transform of A089836.

Cf. A000108, A000142, A001246, A001813.

Sequence in context: A090316 A128578 A186632 * A210909 A009251 A009447

Adjacent sequences: A089832 A089833 A089834 * A089836 A089837 A089838

Keyword

nonn

Author

Antti Karttunen, Dec 05 2003

Status

approved