A126023 a(0)=0, a(1)=1; for n>1, a(n) = a(n-1)*(a(n-1)+a(n-2)).

0, 1, 1, 2, 6, 48, 2592, 6842880, 46842743439360, 2194242933464976548324966400, 4814702051061088283920560140388303599459408453566464000, 23181355840491850372772514246989811472332466216882815765831029699284672633019505150499832539732598430105600000

Offset

0,4

Links

Table of n, a(n) for n=0..11.

Steven R. Finch, Substitution dynamics, January 23, 2014. [Cached copy, with permission of the author]

Index entries for sequences of form a(n+1)=a(n)^2 + ...

Formula

a(n) ~ c^(2^n), where c = 1.130839439573188327984771046199629891088102083459871373699856783789557668... . - Vaclav Kotesovec, Dec 18 2014

Mathematica

a=0; b=1; lst={a, b}; Do[c=(a+b)*b; AppendTo[lst, c]; a=b; b=c, {n, 2*3!}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 05 2009 *)
RecurrenceTable[{a[0]==0, a[1]==1, a[n] == a[n-1]*(a[n-1]+a[n-2])}, a, {n, 0, 10}] (* Vaclav Kotesovec, Dec 18 2014 *)

Prog

(PARI) a=0; b=1; vector(11, i, c=b*(b+a); a=b; b=c; a)

Crossrefs

Cf. A064183.

Sequence in context: A346788 A230053 A245283 * A088679 A161766 A074020

Adjacent sequences: A126020 A126021 A126022 * A126024 A126025 A126026

Keyword

easy,nonn

Author

Franklin T. Adams-Watters, Feb 27 2007

Status

approved