0,1

Sequence is identical to its third differences.

a(n) = -(1/3)*{(n mod 6)+[(n+1) mod 6]-[(n+3) mod 6]-[(n+4) mod 6]}, with n>=0. - Paolo P. Lava (ppl(AT)spl.at), Jul 18 2007

O.g.f.: 2/(x^2-x+1). a(n) = 2*A010892(n) . - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Feb 14 2008

Sequence in context: A045719 A114906 A114700 this_sequence A109265 A035668 A066518

Adjacent sequences: A130769 A130770 A130771 this_sequence A130773 A130774 A130775

sign

Paul Curtz (bpcrtz(AT)free.fr), Jul 14 2007