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

%I #8 Jun 03 2022 12:59:36

%S 1,1,4,10,20,36,64,120,240,499,1060,2314,5252,12360,29632,70992,

%T 168096,392465,905940,2075314,4730052,10735516,24258688,54553000,

%U 122076240,271914499,603183508,1333268098,2937818900,6455143760,14146816640,30929336736,67473335104

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

%F a(0) = 1; a(n) = Sum_{k=0..floor((n-1)/4)} binomial(n+2,4*k+3) * a(k).

%o (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=0, (i-1)\4, binomial(i+2, 4*j+3)*v[j+1])); v;

%Y Cf. A119685, A354695.

%Y Cf. A351817, A352066.

%K nonn

%O 0,3

%A _Seiichi Manyama_, Jun 03 2022