OFFSET
-1,7
COMMENTS
Essentially the same as A074047. [R. J. Mathar, Aug 07 2008]
MATHEMATICA
a[0] = 0; a[1] = 1; a[2] = 1; 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, 0, 15}]
nxt[{a_, b_, c_}]:={b, c, a*b+b*c+a*c}; NestList[nxt, {1, 1, 0}, 20][[;; , 1]] (* Harvey P. Dale, Aug 29 2024 *)
PROG
(PARI) {f23(x, y, z)=x*y+y*z+z*x; a=[0, 1, 1]; for(n=1, 19, a=concat(a, f23(a[n], a[n+1], a[n+2]))); a} \\ M. F. Hasler, Jan 01 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Roger L. Bagula, Aug 30 2006
EXTENSIONS
Edited by N. J. A. Sloane, Oct 08 2006
Extended the sequence by prefixing the two values a(0)=a(-1)=1. - M. F. Hasler, Jan 01 2013
STATUS
approved