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.

A187458 Number of (n+1)X(n+1) 0..1 arrays with all the 2X2 subblocks nonsingular and the array of 2X2 subblock determinants symmetric.

Table of values

n a(n)
1 6
2 26
3 144
4 1272
5 15192
6 286392
7 7648032
8 314011868
9 18986004296
10 1725663296600
11 237096836118080
12 48071903199959400
13 15027587384189632928
14 6819730931931151055960
15 4852231403635188536789728

List of values

[6, 26, 144, 1272, 15192, 286392, 7648032, 314011868, 18986004296, 1725663296600, 237096836118080, 48071903199959400, 15027587384189632928, 6819730931931151055960, 4852231403635188536789728]

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

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