A283820 a(n) = (1 + Sum_{j=1..K-2} a(n-j)*a(n-j-1))/a(n-K) with a(1),...,a(K)=1, where K=7.

1, 1, 1, 1, 1, 1, 1, 6, 11, 76, 911, 70146, 63973151, 4487524623191, 47846849137190094661, 19519446695048425827542253313671, 12288737121834287082853490635842863813970134234101

Offset

1,8

Links

Seiichi Manyama, Table of n, a(n) for n = 1..23

Matthew Christopher Russell, Using experimental mathematics to conjecture and prove theorems in the theory of partitions and commutative and non-commutative recurrences, PhD Dissertation, Mathematics Department, Rutgers University, May 2016; see also.

Mathematica

a[n_]:=If[n<8, 1, (1 + Sum[a[n - j] * a[n - j - 1], {j, 5}])/a[n - 7]]; Table[a[n], {n, 1, 17}] (* Indranil Ghosh, Mar 17 2017 *)

Prog

(PARI) a(n) = if(n<8, 1, (1 + sum(j=1, 5, a(n - j) * a(n - j - 1)))/a(n - 7));
for(n=1, 17, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 17 2017

Crossrefs

Sequence in context: A001543 A077705 A077697 * A332659 A219702 A013321

Adjacent sequences: A283817 A283818 A283819 * A283821 A283822 A283823

Keyword

nonn

Author

N. J. A. Sloane, Mar 17 2017

Extensions

More terms from Indranil Ghosh, Mar 17 2017

Status

approved