A066046 a(1) = 1; a(2) = 2; a(3) = 3; a(n+3) = a(n+2)*a(n+1) + a(n+1)*a(n) + a(n)*a(n+2).

1, 2, 3, 11, 61, 887, 64535, 61233287, 4006061344659, 245562839177678209243, 983754834334464538655453075619011, 241573634114919799405450621896403920334941569392914059

Offset

1,2

Links

Harry J. Smith, Table of n, a(n) for n = 1..18

Mathematica

a[1] = 1; a[2] = 2; a[3] = 3; a[n_] := a[n] = a[n - 1]*a[n - 2] + a[n - 2]*a[n - 3] + a[n - 1]*a[n - 3]; Table[a[n], {n, 1, 13} ]
nxt[{a_, b_, c_}]:={b, c, a*b+a*c+b*c}; Transpose[NestList[nxt, {1, 2, 3}, 12]][[1]] (* Harvey P. Dale, Jan 23 2015 *)

Prog

(PARI) { for (n = 1, 18, if (n>3, a=a1*a2 + a2*a3 + a3*a1; a3=a2; a2=a1; a1=a, if (n==1, a=a3=1, if (n==2, a=a2=2, a=a1=3))); write("b066046.txt", n, " ", a) ) } \\ Harry J. Smith, Nov 08 2009

Crossrefs

Sequence in context: A110482 A242366 A105217 * A065597 A256394 A219513

Adjacent sequences: A066043 A066044 A066045 * A066047 A066048 A066049

Keyword

nonn

Author

Benoit Cloitre, Dec 29 2001

Extensions

More terms from Robert G. Wilson v, Dec 31 2001

Status

approved