0,2

For n >= 3: if n = 2*p^m with a prime p then a(n) = p otherwise a(n) = 1. - Ola Veshta (olaveshta(AT)my-deja.com), Jun 01 2001

with(numtheory, cyclotomic); f := n->subs(x=-1, cyclotomic(n, x)); seq(f(i), i=0..64);

Sequence in context: A029277 A077905 A131331 this_sequence A029276 A109248 A131866

Adjacent sequences: A020510 A020511 A020512 this_sequence A020514 A020515 A020516

sign

Simon Plouffe (simon.plouffe(AT)gmail.com)