0,4

Partial sums are in A107240.

a(n) = (A000213(n))^2. O.g.f.: -(x^3-x^2+3x-1)(1+x)^2/((x^3-x^2-x-1)(x^3+x^2+3x-1)). a(n) = 2a(n-1) +3a(n-2) +6a(n-3) -a(n-4) -a(n-6).

Cf. A000213, A085697.

Sequence in context: A125997 A166103 A110970 this_sequence A147413 A066137 A147428

Adjacent sequences: A141580 A141581 A141582 this_sequence A141584 A141585 A141586

easy,nonn

R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 19 2008