A117946 a(3n)=0, a(3n+1)/a(1)=a(3n+2)/a(2)=A059151(n).

0, 1, -2, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 4, -8, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 4, -8, 0, 2, -4, 0, 4, -8, 0, 8, -16, 0, 4, -8, 0, 2, -4, 0, 4, -8, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 4, -8, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 1, -2, 0, 2, -4, 0, 4, -8, 0, 2, -4, 0, 4, -8, 0, 8, -16, 0, 4, -8

Offset

0,3

Comments

Second column of A117939.

Links

Table of n, a(n) for n=0..98.

Formula

a(n)=sum{k=0..n, L((n-j)/3)*L(C(n,k)/3)} where L(j/p) is the Legendre symbol of j and p.

Crossrefs

Sequence in context: A136717 A261685 A136716 * A061930 A209691 A221683

Adjacent sequences: A117943 A117944 A117945 * A117947 A117948 A117949

Keyword

easy,sign

Author

Paul Barry, Apr 05 2006

Status

approved