cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A359513 Number of partitions of n into at most 4 positive Fibonacci numbers (with a single type of 1).

Original entry on oeis.org

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, 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, 6, 3, 10, 5, 7, 9, 5, 8, 5, 2, 9, 4, 7, 6, 2, 8, 4, 3, 8, 1, 4, 1
Offset: 0

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Author

Ilya Gutkovskiy, Jan 03 2023

Keywords

Crossrefs

Programs

  • Maple
    h:= proc(n) option remember; `if`(n<1, 0, `if`((t->
          issqr(t+4) or issqr(t-4))(5*n^2), n, h(n-1)))
        end:
    b:= proc(n, i) option remember; `if`(n=0 or i=1, x^n,
          b(n, h(i-1))+expand(x*b(n-i, h(min(n-i, i)))))
        end:
    a:= n-> (p-> add(coeff(p, x, i), i=0..4))(b(n, h(n))):
    seq(a(n), n=0..87);  # Alois P. Heinz, Jan 03 2023
  • Mathematica
    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]]]];
    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]]]]];
    a[n_] := Sum[Coefficient[#, x, i], {i, 0, 4}]&[b[n, h[n]]];
    Table[a[n], {n, 0, 87}] (* Jean-François Alcover, May 26 2023, after Alois P. Heinz *)

Formula

a(n) = Sum_{k=0..4} A319394(n,k). - Alois P. Heinz, Jan 03 2023