A368013 - OEIS

%I #9 Dec 08 2023 09:57:23

%S 1,-1,-1,5,11,-91,-301,3485,15371,-228811,-1261501,22951565,151846331,

%T -3264973531,-25201039501,625232757245,5515342166891,-155079142742251,

%U -1538993024478301,48364005482108525,533289474412481051,-18523127502677822971

%N Expansion of e.g.f. 1/(1 - exp(x) + exp(2*x)).

%F a(0) = 1; a(n) = Sum_{k=1..n} (1 - 2^k) * binomial(n,k) * a(n-k).

%o (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, (1-2^j)*binomial(i, j)*v[i-j+1])); v;

%Y Cf. A004700, A368016.

%K sign

%O 0,4

%A _Seiichi Manyama_, Dec 08 2023