OFFSET

1,2

COMMENTS

Every term is a power of 2 and the geometric mean of first n terms is 2 for n >1. Rearrangement of powers of 2.

FORMULA

a(n) = 2^A002251(n-1). - David Wasserman, Mar 07 2005

EXAMPLE

a(5) = 128: the product of the first five terms is 1*4*2*32*128 = 2^15 = 8^5; 4 gives 4^5, also a 5th power, but 4 is already included.

PROG

(PARI) v=[1]; n=1; while(n<10^4, p=n*prod(i=1, #v, v[i]); if(ispower(p, #v+1)&&!vecsearch(vecsort(v), n), v=concat(v, n); n=1); n++); v \\ Derek Orr, May 27 2015

CROSSREFS

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Jul 26 2003

EXTENSIONS

More terms from David Wasserman, Mar 07 2005

STATUS

approved