0,2

a(n)=sum{k=0..9n, L(C(9n,k)/3)*10^k} where L(j/p) is the Legendre symbol of j and p.

Sequence in context: A017277 A017517 A017649 this_sequence A096213 A048939 A095733

Adjacent sequences: A117976 A117977 A117978 this_sequence A117980 A117981 A117982

easy,nonn

Paul Barry (pbarry(AT)wit.ie), Apr 06 2006