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.

A134134 Triangle of numbers obtained from the partition array A134133.

Original entry on oeis.org

1, 2, 1, 6, 2, 1, 24, 10, 2, 1, 120, 36, 10, 2, 1, 720, 204, 44, 10, 2, 1, 5040, 1104, 228, 44, 10, 2, 1, 40320, 7776, 1272, 244, 44, 10, 2, 1, 362880, 57600, 8760, 1320, 244, 44, 10, 2, 1, 3628800, 505440, 63936, 9096, 1352, 244, 44, 10, 2, 1
Offset: 1

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Author

Wolfdieter Lang, Oct 12 2007

Keywords

Comments

In the same manner the unsigned Lah triangle A008297 is obtained from the partition array A130561.

Examples

			[1];[2,1];[6,2,1];[24,10,2,1];[120,36,10,2,1];...
a(4,2)=10 from the sum over the numbers related to the partitions (1,3) and (2^2), namely
1!^1*3!^1 + 2!^2 = 6+4 = 10.
		

Crossrefs

Row sums A077365. Alternating row sums A134135.

Formula

a(n,m)=sum(product(j!^e(n,m,k,j),j=1..n),k=1..p(n,m)) if n>=m>=1, else 0, with p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,k,j) is the exponent of j in the k-th m part partition of n.