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A121810 a(n) = a(n - 1)*a(n - 2) + a(n - 2)*a(n - 3) + a(n - 1)*a(n - 3). 3
1, 1, 0, 1, 1, 1, 3, 7, 31, 331, 12795, 4642051, 60935796571, 283646808320375611, 17285560913056915909539455163, 4902995236325455290013100337511909917402705547 (list; graph; refs; listen; history; text; internal format)
OFFSET
-1,7
COMMENTS
Essentially the same as A074047. [R. J. Mathar, Aug 07 2008]
LINKS
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}]
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
Cf. A203761 and references therein.
Cf. A074047.
Sequence in context: A277028 A156895 A074047 * A081475 A123212 A213437
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

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Last modified February 21 16:55 EST 2024. Contains 370237 sequences. (Running on oeis4.)