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.

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A304036 Number of partitions of n into at most 2 copies of 1!, 3 copies of 2!, 4 copies of 3!, ... .

Original entry on oeis.org

1, 1, 2, 1, 2, 1, 3, 2, 3, 1, 2, 1, 3, 2, 3, 1, 2, 1, 3, 2, 3, 1, 2, 1, 4, 3, 5, 2, 4, 2, 5, 3, 4, 1, 2, 1, 3, 2, 3, 1, 2, 1, 3, 2, 3, 1, 2, 1, 4, 3, 5, 2, 4, 2, 5, 3, 4, 1, 2, 1, 3, 2, 3, 1, 2, 1, 3, 2, 3, 1, 2, 1, 4, 3, 5, 2, 4, 2, 5, 3, 4, 1, 2, 1, 3, 2, 3, 1, 2
Offset: 0

Views

Author

Seiichi Manyama, May 05 2018

Keywords

Examples

			a(6) = 3 because we have [6], [2,2,2] and [2,2,1,1].
		

Crossrefs

Formula

G.f.: Product_{j>=1} Sum_{k=0..j+1} x^(k*j!) = Product_{j>=1} (1-x^((j+1)!+j!))/(1-x^(j!)).

A303940 Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1-x^(j*(j+k)))/(1-x^j). in powers of x.

Original entry on oeis.org

1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 2, 2, 3, 2, 1, 1, 2, 3, 4, 4, 3, 1, 1, 2, 3, 4, 5, 5, 3, 1, 1, 2, 3, 5, 6, 8, 7, 5, 1, 1, 2, 3, 5, 6, 9, 10, 10, 5, 1, 1, 2, 3, 5, 7, 10, 12, 14, 13, 8, 1, 1, 2, 3, 5, 7, 10, 13, 17, 18, 17, 9, 1, 1, 2, 3, 5, 7, 11, 14, 19, 23, 25, 22, 13
Offset: 0

Views

Author

Seiichi Manyama, May 03 2018

Keywords

Comments

A(n,k) is the number of partitions of n into at most 0+k copies of 1, 1+k copies of 2, 2+k copies of 3, ... .

Examples

			Square array begins:
   1, 1, 1, 1,  1,  1,  1,  1, ...
   0, 1, 1, 1,  1,  1,  1,  1, ...
   1, 1, 2, 2,  2,  2,  2,  2, ...
   1, 2, 2, 3,  3,  3,  3,  3, ...
   1, 3, 4, 4,  5,  5,  5,  5, ...
   2, 4, 5, 6,  6,  7,  7,  7, ...
   3, 5, 8, 9, 10, 10, 11, 11, ...
		

Crossrefs

Columns k=0..2 give A087153, A052335, A303939.
Main diagonal gives A000041.
Showing 1-2 of 2 results.