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.

A143229 a(n) = A000041(n) * A000070(n).

Original entry on oeis.org

1, 2, 8, 21, 60, 133, 330, 675, 1474, 2910, 5838, 10920, 20944, 37673, 68580, 120384, 211365, 359964, 614845, 1022630, 1701678, 2776752, 4517016, 7232565, 11557350, 18201568, 28579152, 44373420, 68634280, 105109125, 160436916, 242692582, 365853180, 547346709
Offset: 0

Views

Author

Gary W. Adamson, Jul 31 2008

Keywords

Comments

Row sums of triangle A143228.

Examples

			a(4) = 60 = A000041(4) * A000070(4) = 5 * 12.
a(4) = 60 = sum of row 4 terms of row 4 in triangle A143228: (5 + 5 + 10 + 15 + 25).
		

Crossrefs

Programs

  • Magma
    A143229:= func< n | NumberOfPartitions(n)*(&+[NumberOfPartitions(k): k in [0..n]]) >;
    [A143229(n): n in [0..50]]; // G. C. Greubel, Aug 27 2024
    
  • Mathematica
    A143229[n_]:= PartitionsP[n]*Sum[PartitionsP[k], {k, 0, n}];
    Table[A143229[n], {n,0,50}] (* G. C. Greubel, Aug 27 2024 *)
  • SageMath
    def p(n): return number_of_partitions(n) # A000041
    def A143229(n): return p(n)*sum(p(k) for k in range(n+1))
    [A143229(n) for n in range(51)] # G. C. Greubel, Aug 27 2024

Formula

a(n) = A000041(n) * A000070(n).
a(n) ~ exp(2*sqrt(2*n/3)*Pi)/(8*sqrt(6)*Pi*n^(3/2)) * (1 + (5*Pi/(12*sqrt(6)) - sqrt(3/2)/Pi)/sqrt(n) + (13*Pi^2/1728 - 19/48)/n). - Vaclav Kotesovec, Nov 04 2016

Extensions

More terms from Vaclav Kotesovec, Nov 04 2016