Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #6 Mar 12 2017 12:10:45
%S 0,1,1,-1,1,-1,-1,-1,1,1,-1,1,-1,1,-1,1,1,1,1,-1,-1,1,1,1,-1,1,1,-1,
%T -1,1,1,1,1,-1,1,1,1,-1,-1,-1,-1,-1,1,-1,1,-1,1,-1,-1,1,1,-1,1,-1,-1,
%U -1,-1,1,1,1,1,1,1,-1,1,-1,-1,1,1,-1,1,-1,1,1,-1,-1,-1,-1,-1,1,-1,1
%N Legendre symbol (n,257).
%C 257 is the 3rd Fermat prime, A019434(3).
%H A. Karttunen, <a href="/A165573/b165573.txt">Table of n, a(n) for n = 0..257</a>
%o (PARI) a(n) = kronecker(n, 257); \\ _Michel Marcus_, Mar 12 2017
%Y Partial sums: A165575.
%K sign,mult
%O 0,1
%A _Antti Karttunen_, Sep 22 2009