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.

A179313 Triangle T(n,k) read by rows: product of the compositorial weight of the k-th partition of n times A074664(.) applied to each part.

Original entry on oeis.org

1, 1, 1, 2, 2, 1, 6, 4, 1, 3, 1, 22, 12, 4, 6, 3, 4, 1, 92, 44, 12, 4, 18, 12, 1, 8, 6, 5, 1, 426, 184, 44, 24, 66, 36, 12, 6, 24, 24, 4, 10, 10, 6, 1, 2146, 852, 184, 88, 36, 276, 132, 72, 18, 12, 88, 72, 24, 24, 1, 30, 40, 10, 12, 15, 7, 1, 11624, 4292, 852, 368, 264, 1278, 552
Offset: 1

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Author

Alford Arnold, Jul 11 2010

Keywords

Comments

Row n has A000041(n) entries. T(n,k) is the product of A074664(a_i) over all parts a_i
multiplied by the compositorial weight A048996(n,k) of the k-th partition (Abramowitz-Stegun order)
of n = sum_i a_i.
Summing also over the partitions with a common number of parts would create A127743.
In row n=4, for example, the partitions 3+1 and 2+2, each with 2 parts, are represented by
T(4,2)=4 and T(4,3)= 1 here, and the sum 4+1=5 of the entries is the single entry A127743(4,.).
In this sense, the table is a refinement of A127743.

Examples

			T(6,3) represents the 3rd partition of 6, namely 2+4. A074664(2)*A074664(4) = 1*6 is multiplied
by the weight A048996([2,4]) = 2!/1!/1! =2, and T(6,3) =1*6*2=12.
T(6,5) represents the 5th partition of 6, namely 1+1+4. A074664(1)*A074664(1)*A074664(4) = 1*1*6 is multiplied
by the weight A048996([1,1,4]) = 3!/2!/1! =3, and T(6,5) =1*1*6*3.
T(7,6) represents the 6th partition of 7, namely 1+2+4. A074664(1)*A074664(2)*A074664(4) = 1*1*6 is multiplied
the weight A048996([1,2,4]) = 3!/1!/1!/1! =6, and T(7,6) =1*1*6*6.
The triangle starts
1;
1,1;
2,2,1;
6,4,1,3,1;
22,12,4,6,3,4,1;
92,44,12,4,18,12,1,8,6,5,1;
426,184,44,24,66,36,12,6,24,24,4,10,10,6,1;
		

References

  • M. Abramowitz and I. A. Stegun, Handbook of Mathematical Functions, p. 831

Crossrefs

Formula

T(n,k) = A048996(n,k) * A179380(n,k).
sum_{k=1..A000041(n)} T(n,k) = A000110(n).

Extensions

Edited and extended by R. J. Mathar, Jul 16 2010