A165426 a(1) = 1, a(2) = 8, a(n) = product of the previous terms for n >= 3.

1, 8, 8, 64, 4096, 16777216, 281474976710656, 79228162514264337593543950336, 6277101735386680763835789423207666416102355444464034512896

Offset: 1

Author

Jaroslav Krizek, Sep 17 2009

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..13

Programs

Mathematica

a[1]:= 1; a[2]:= 8; a[n_]:= Product[a[j], {j,1,n-1}]; Table[a[n],{n,1, 12}] (* G. C. Greubel, Oct 19 2018 *)

PARI

{a(n) = if(n==1, 1, if(n==2, 8, prod(j=1,n-1, a(j))))};
for(n=1,10, print1(a(n), ", ")) \\ G. C. Greubel, Oct 19 2018

Formula

a(1) = 1, a(2) = 8, a(n) = Product_{i=1..n-1} a(i), n >= 3.

a(1) = 1, a(2) = 8, a(n) = A001018(2^(n-3)) = 8^(2^(n-3)), n >= 3.

a(1) = 1, a(2) = 8, a(3) = 8, a(n) = (a(n-1))^2, n >= 4.

a(n) = 8^A166444(n). [uncovered by sequencedb.net]. - R. J. Mathar, Jun 30 2021