A359513 - OEIS

%I #13 May 26 2023 05:19:14

%S 1,1,2,3,4,5,6,6,8,7,8,8,8,8,8,8,9,8,9,8,8,8,7,8,9,7,10,8,8,9,7,8,8,4,

%T 8,5,8,9,6,10,8,6,10,6,9,8,5,9,6,6,8,4,8,4,1,8,4,7,9,5,10,7,6,10,6,8,

%U 6,3,10,5,7,9,5,8,5,2,9,4,7,6,2,8,4,3,8,1,4,1

%N Number of partitions of n into at most 4 positive Fibonacci numbers (with a single type of 1).

%H Alois P. Heinz, <a href="/A359513/b359513.txt">Table of n, a(n) for n = 0..20000</a>

%F a(n) = Sum_{k=0..4} A319394(n,k). - _Alois P. Heinz_, Jan 03 2023

%p h:= proc(n) option remember; `if`(n<1, 0, `if`((t->

%p       issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))

%p     end:

%p b:= proc(n, i) option remember; `if`(n=0 or i=1, x^n,

%p       b(n, h(i-1))+expand(x*b(n-i, h(min(n-i, i)))))

%p     end:

%p a:= n-> (p-> add(coeff(p, x, i), i=0..4))(b(n, h(n))):

%p seq(a(n), n=0..87);  # _Alois P. Heinz_, Jan 03 2023

%t h[n_] := h[n] = If[n < 1, 0, With[{t = 5 n^2}, If[IntegerQ @ Sqrt[t + 4] || IntegerQ @ Sqrt[t - 4], n, h[n - 1]]]];

%t b[n_, i_] := b[n, i] = If[n == 0 || i == 1, x^n, b[n, h[i - 1]] + Expand[x*b[n - i, h[Min[n - i, i]]]]];

%t a[n_] := Sum[Coefficient[#, x, i], {i, 0, 4}]&[b[n, h[n]]];

%t Table[a[n], {n, 0, 87}] (* _Jean-François Alcover_, May 26 2023, after _Alois P. Heinz_ *)

%Y Cf. A000045, A003107, A319394, A319397, A359511, A359512, A359516.

%K nonn

%O 0,3

%A _Ilya Gutkovskiy_, Jan 03 2023