1,2

Table of n, a(n) for n=1..75.

(PARI) {an=vector(1000); }{a(n)=if(n<0, 0, an[n]); }{an[1]=1; }{for(n=2, 1000, an[n]=-sum(k=1, n-1, (-1)^a(k)*floor(n/k))}

Sequence in context: A117894 A177762 A109380 * A011020 A181512 A076019

Adjacent sequences: A167751 A167752 A167753 * A167755 A167756 A167757

nonn

Benoit Cloitre, Nov 10 2009

approved