A065653 a(0) = 0, a(1) = 1, a(n) = a(n-2)*a(n-2) + 2 for n > 1.

0, 1, 2, 3, 6, 11, 38, 123, 1446, 15131, 2090918, 228947163, 4371938082726, 52416803445748571, 19113842599189892819591078, 2747521283470239265968814548542043, 365338978906606237729724396156395693696687137202086

Offset: 0

Author

Reinhard Zumkeller, Nov 10 2001

Keywords

• nonn

Links

• Harry J. Smith, Table of n, a(n) for n=0,...,24

Crossrefs

Cf. A065652

Programs

Mathematica

RecurrenceTable[{a[0]==0,a[1]==1,a[n]==a[n-2]^2+2},a,{n,20}] (* Harvey P. Dale, Aug 19 2013 *)

PARI

a(n)=if(n<2, n>0, 2+a(n-2)^2) /* Michael Somos, Mar 25 2006 */

PARI

{ for (n=0, 24, if (n>1, a=a2^2 + 2; a2=a1; a1=a, if (n, a=a1=1, a=a2=0)); write("b065653.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 25 2009

Formula

A102847(n)=a(2n+1), A072191(n)=a(2n).

Extensions

One more term from Harvey P. Dale, Aug 19 2013