A283920 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=8.

1, 1, 1, 1, 1, 1, 1, 1, 7, 13, 103, 1441, 149863, 216102445, 32385976817479, 6998688806356507453627, 32379910490774089036757549734714267, 17432070546354327896489623045874879995780253657133907303

Offset

1,9

Links

Seiichi Manyama, Table of n, a(n) for n = 1..24

Mathematica

a[n_]:= If[n<9, 1, (1 + Sum[a[n - j] * a[n -j - 1], {j, 6}])/a[ n - 8]]; Table[a[n], {n, 20}] (* Indranil Ghosh, Mar 18 2017 *)

Prog

(PARI) a(n) = if(n<9, 1, (1 + sum(j=1, 6, a(n - j) * a(n - j - 1)))/a(n - 8));
for(n=1, 24, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 18 2017

Crossrefs

Cf. A077458 (K=4), A283819 (K=5), A283918 (K=6), A283820 (K=7), this sequence (K=8), A283821 (K=9).

Sequence in context: A323468 A035030 A046519 * A128351 A192894 A367597

Adjacent sequences: A283917 A283918 A283919 * A283921 A283922 A283923

Keyword

nonn

Author

Seiichi Manyama, Mar 17 2017

Status

approved