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A063402 a(0)=0; a(1)=1; a(2)=2; a(n)= a(n-1) + a(n-2)*a(n-3). 1
0, 1, 2, 2, 4, 8, 16, 48, 176, 944, 9392, 175536, 9041584, 1657675696, 1588781164720, 14989602831307184, 2633698912621747952304, 23815201278713350097371300784, 39478100701260806183512640492975852720 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Harry J. Smith, Table of n, a(n) for n = 0..29

MATHEMATICA

nxt[{a_, b_, c_}]:={b, c, c+a*b}; NestList[nxt, {0, 1, 2}, 20][[All, 1]] (* Harvey P. Dale, Oct 16 2020 *)

PROG

(PARI) { for (n = 0, 29, if (n>2, a=a1 + a2*a3; a3=a2; a2=a1; a1=a, if (n==0, a=a3=0; a2=1; a1=2, if (n==1, a=1, a=2))); write("b063402.txt", n, " ", a) ) } \\ Harry J. Smith, Aug 20 2009

CROSSREFS

Cf. A006888.

Sequence in context: A123593 A122748 A108774 * A175195 A139800 A168058

Adjacent sequences:  A063399 A063400 A063401 * A063403 A063404 A063405

KEYWORD

nonn,easy

AUTHOR

Olivier Gérard, Jul 16 2001

STATUS

approved

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Last modified December 5 08:36 EST 2021. Contains 349543 sequences. (Running on oeis4.)