A367694 - OEIS

%I #10 Nov 27 2023 06:25:28

%S 1,0,1,0,1,0,1,0,1,1,2,2,3,3,4,4,5,6,8,10,13,16,20,24,29,35,43,53,66,

%T 82,102,126,155,190,233,286,352,435,537,664,819,1011,1244,1532,1884,

%U 2322,2860,3528,4349,5366,6614,8154,10044,12377,15247,18791,23156,28546

%N G.f. A(x) satisfies A(x) = 1 / ((1 + x) * (1 - x * A(x^4))).

%F a(n) = (-1)^n + Sum_{k=0..floor((n-1)/4)} a(k) * a(n-1-4*k).

%o (PARI) a_vector(n) = my(v=vector(n+1)); for(i=0, n, v[i+1]=(-1)^i+sum(j=0, (i-1)\4, v[j+1]*v[i-4*j])); v;

%Y Cf. A005043, A351973, A367693.

%Y Cf. A367660, A367692.

%K nonn

%O 0,11

%A _Seiichi Manyama_, Nov 27 2023