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.

A187701 Number of (n+1)X(n+1) 0..2 arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal.

This page as a plain text file.
%I A187701 #7 Jul 22 2025 10:53:14
%S A187701 31,1489,72,5030,36,7410,474,176936
%N A187701 Number of (n+1)X(n+1) 0..2 arrays with each 2X2 subblock off diagonal and antidiagonal nonsingular and the array of 2X2 subblock determinants antisymmetric about the diagonal and antidiagonal.
%C A187701 Column 2 of A187705
%e A187701 Some solutions for 4X4
%e A187701 ..0..2..0..0....0..0..1..1....0..0..2..1....0..2..0..0....0..0..1..0
%e A187701 ..0..1..1..1....2..1..1..1....2..1..2..1....0..2..1..2....2..2..1..0
%e A187701 ..2..2..2..0....1..1..1..2....0..1..2..2....1..2..1..0....1..2..1..2
%e A187701 ..0..0..1..0....1..1..0..0....0..1..0..0....0..0..1..0....1..2..0..0
%K A187701 nonn
%O A187701 1,1
%A A187701 _R. H. Hardin_ Mar 12 2011

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

Content is available under The OEIS End-User License Agreement.