A115031 a(n) = a(n-1)^a(n-1) - a(n-2)^a(n-2) with a(0)=1 and a(1)=2.

1, 2, 3, 23, 20880467999847912034355032910540

Offset

0,2

Comments

a(6) is too large to include.

Links

Table of n, a(n) for n=0..4.

Example

23^23 - 3^3 = 20880467999847912034355032910540.

Mathematica

a[0] := 1; a[1] := 2; a[n_] := a[n] = a[n - 1]^a[n - 1] - a[n - 2]^a[n - 2]; Table[Floor[a[n]], {n, 0, 4}] (* G. C. Greubel, Dec 20 2017 *)
nxt[{a_, b_}]:={b, b^b-a^a}; NestList[nxt, {1, 2}, 4][[All, 1]]//Quiet (* Harvey P. Dale, May 10 2021 *)

Crossrefs

Sequence in context: A260420 A241661 A260071 * A030418 A329456 A037277

Adjacent sequences: A115028 A115029 A115030 * A115032 A115033 A115034

Keyword

easy,nonn

Author

Giovanni Teofilatto, Feb 26 2006

Extensions

Definition corrected and example added by N. J. A. Sloane, Jun 09 2017

Status

approved