A271952 Somos's sequence {b(6,n)} defined in comment in A078495: a(0)=a(1)=...=a(14)=1; for n>=15, a(n)=(a(n-1)*a(n-14)+a(n-7)*a(n-8))/a(n-15).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 10, 16, 28, 48, 78, 120, 176, 432, 728, 1120, 1736, 2832, 4864, 8576, 20224, 63808, 162624, 348224, 668288, 1204736, 2114560, 6175744, 13394432, 34860544, 104595968, 304683008, 807587840

Offset

0,16

Links

Seiichi Manyama, Table of n, a(n) for n = 0..440

Mathematica

a[k_, n_]:=a[k, n]=If[n>2k+2, (a[k, (n-1)]*a[k, (n-2k-2)]+a[k, (n-k-1)]*a[k, (n-k-2)])/a[k, (n-2k-3)], 1];
Map[a[6, #]&, Range[0, 50]] (* Peter J. C. Moses, Apr 17 2016 *)

Prog

(PARI) {a(n) = if(n<= 15, 1, (a(n-1)*a(n-14) + a(n-7)*a(n-8))/a(n-15))}; for(n=1, 50, print1(a(n), ", ")) \\ G. C. Greubel, Jul 30 2018
(Magma) [n le 15 select 1 else (Self(n-1)*Self(n-14)+Self(n-7)*Self(n-8))/Self(n-15): n in [1..60]]; // G. C. Greubel, Jul 30 2018

Crossrefs

Cf. A006721, A078495, A268199, A271948, A271949, A271950.

Sequence in context: A218550 A127273 A143287 * A033073 A369406 A306111

Adjacent sequences: A271949 A271950 A271951 * A271953 A271954 A271955

Keyword

nonn

Author

Vladimir Shevelev and Peter J. C. Moses, Apr 17 2016

Status

approved