OFFSET
1,1
FORMULA
a(n) =if (2^n-1)/(2*n*Prime[m]-1)=Integer then n
MATHEMATICA
digits=700 a=Delete[Union[Flatten[Table[If[ IntegerQ[(2^n-1)/(2*n*Prime[m]-1)]==True, n, 0], {n, 1, digits}, {m, 1, digits}]]], 1]
CROSSREFS
KEYWORD
nonn,uned
AUTHOR
Roger L. Bagula, Jul 06 2004
STATUS
approved