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.

A172806 Number of n X n of nonnegative integers with all row and column sums equal to 4.

Table of values

n a(n)
0 1
1 1
2 5
3 120
4 10147
5 2224955
6 1047649905
7 936670590450
8 1455918295922650
9 3680232136895819610
10 14356628851597700179050
11 82857993930808028192521800
12 683327637694741065563262206250
13 7821620120684573354895941635688250

List of values

[1, 1, 5, 120, 10147, 2224955, 1047649905, 936670590450, 1455918295922650, 3680232136895819610, 14356628851597700179050, 82857993930808028192521800, 683327637694741065563262206250, 7821620120684573354895941635688250]

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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