A059475 - cp's OEIS frontend

A059475 Number of 2n X 2n half-turn symmetric alternating-sign matrices (HTSASM's).

n	a(n)
0	1
1	2
2	10
3	140
4	5544
5	622908
6	198846076
7	180473355920
8	465904151957920
9	3422048076740462480
10	71525763221287897903500
11	4254840960508487045451825000
12	720428791920558617462950575000000
13	347230535542092373572967034254050000000

[1, 2, 10, 140, 5544, 622908, 198846076, 180473355920, 465904151957920, 3422048076740462480, 71525763221287897903500, 4254840960508487045451825000, 720428791920558617462950575000000, 347230535542092373572967034254050000000]

cp's OEIS Frontend

A059475 Number of 2n X 2n half-turn symmetric alternating-sign matrices (HTSASM's).

Table of values

List of values