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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 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 FrÃ¶hlich, 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 September 29 03:42 EDT 2020. Contains 337420 sequences. (Running on oeis4.)