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A330581 a(0) = 2; thereafter a(n) = a(n - 1)^n + 1. 0
2, 3, 10, 1001, 1004006004002, 1020191144865623440455270145683555422808365843606721760320033 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Note that this could be extended backwards to a(-1), and any nonzero value x for a(-1) would work, since x^0 + 1 = 2.

LINKS

Table of n, a(n) for n=0..5.

David Johnson-Davies, Recursive functions without a base case

MAPLE

a:= proc(n) option remember; `if`(n<0, %,

      1 + a(n-1)^n)

    end:

seq(a(n), n=0..5);  # Alois P. Heinz, Dec 18 2019

MATHEMATICA

a[0] = 2; a[n_] := a[n] = a[n - 1]^n + 1; Array[a, 6, 0] (* Amiram Eldar, Dec 19 2019 *)

PROG

(Lisp) (defun a (n) (+ (if (zerop n) 1 (expt (a (- n 1)) n)) 1))

(PARI) a(n) = if(n==0, 2, a(n-1)^n+1) \\ Felix Fröhlich, Dec 18 2019

CROSSREFS

Cf. A000522, A182242.

Sequence in context: A290638 A330294 A270442 * A184163 A218271 A128125

Adjacent sequences:  A330578 A330579 A330580 * A330582 A330583 A330584

KEYWORD

nonn

AUTHOR

David Johnson-Davies, Dec 18 2019

EXTENSIONS

Edited by N. J. A. Sloane, Dec 27 2019

STATUS

approved

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Last modified July 6 02:36 EDT 2020. Contains 335475 sequences. (Running on oeis4.)