A165429 a(1) = 1; a(n) = (Sum_{i=1..n-1} a(i))^n for n >= 2.

1, 1, 8, 10000, 100501001000500100000

Offset

1,3

Comments

a(6) has 120 digits (1006016...1000000).

Links

G. C. Greubel, Table of n, a(n) for n = 1..7

Example

a(4) = (a(1) + a(2) + a(3))^4 = (1 + 1 + 8)^4 = 10^4 = 10000.

Mathematica

a[1]:= 1; a[n_]:= (Sum[a[j], {j, 1, n-1}])^n; Table[a[n], {n, 1, 7}] (* G. C. Greubel, Oct 19 2018 *)

Prog

(PARI) {a(n) = if(n==1, 1, (sum(j=1, n-1, a(j)))^n)};
for(n=1, 7, print1(a(n), ", ")) \\ G. C. Greubel, Oct 19 2018

Crossrefs

Sequence in context: A055308 A188890 A175881 * A343475 A242852 A079235

Adjacent sequences: A165426 A165427 A165428 * A165430 A165431 A165432

Keyword

nonn

Author

Jaroslav Krizek, Sep 17 2009

Extensions

Edited by N. J. A. Sloane, Oct 15 2009

Status

approved