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.

A214430 Triangle read by rows, where T(n,m) is sum of the absolute values of the m-th column (in lexicographic ordering) in the character table of S_n.

Original entry on oeis.org

1, 2, 2, 4, 2, 3, 10, 4, 6, 3, 4, 26, 8, 6, 6, 6, 4, 5, 76, 20, 12, 20, 12, 6, 12, 8, 8, 5, 6, 232, 52, 24, 20, 30, 12, 18, 12, 16, 8, 12, 10, 10, 6, 7, 764, 148, 52, 36, 76, 78, 24, 18, 24, 24, 36, 12, 20, 12, 20, 20, 10, 15, 12, 12, 7, 8, 2620, 460, 148, 76, 76, 208, 56, 32, 56, 40, 24, 54, 100, 28, 20, 20, 20, 20, 50
Offset: 1

Views

Author

Kyle Petersen, Jul 17 2012

Keywords

Comments

Ordering on partitions is lexicographic, where partitions themselves are written in decreasing order, e.g., for n=5, the order is [1,1,1,1,1] < [2,1,1,1] < [2,2,1] < [3,1,1] < [3,2] < [4,1] < [5].

Examples

			The character table for S_3 is / 1 1 1 / 2 0 -1 / 1 -1 1 / and so T(3,1)=4, T(3,2)=2, and T(3,3)=3.
Displayed as a triangle:
1
2, 2
4, 2, 3
10, 4, 6, 3, 4
26, 8, 6, 6, 6, 4, 5
76, 20, 12, 20, 12, 6, 12, 8, 8, 5, 6
232, 52, 24, 20, 30, 12, 18, 12, 16, 8, 12, 10, 10, 6, 7
764, 148, 52, 36, 76, 78, 24, 18, 24, 24, 36, 12, 20, 12, 20, 20, 10, 15, 12, 12, 7, 8
		

Crossrefs

Equal to A164341 for n<=7, row sums given in A214418. First column, corresponding to partition [1,1,...,1], is given by A000085.

Programs

  • Maple
    #For row n, we have the following.
    P:=combinat[partition](n):
    seq(add(abs(combinat[Chi](l, m)), l in P), m in P);