A370396 - cp's OEIS frontend

A370396 Number of nonnegative integer matrices with sum of entries equal to 2n or 2n+1, no zero rows or columns, which are symmetric about both diagonals.

n	a(n)
0	1
1	3
2	13
3	63
4	347
5	2061
6	13219
7	89877
8	646009
9	4866339
10	38305573
11	313535631
12	2661927255
13	23367856281
14	211680786375
15	1974332847177
16	18929186519705
17	186249976522155
18	1878195826349765
19	19386702579997095
20	204603867473735387
21	2205553917952342605
22	24261717301000314867

[1, 3, 13, 63, 347, 2061, 13219, 89877, 646009, 4866339, 38305573, 313535631, 2661927255, 23367856281, 211680786375, 1974332847177, 18929186519705, 186249976522155, 1878195826349765, 19386702579997095, 204603867473735387, 2205553917952342605, 24261717301000314867]

cp's OEIS Frontend

A370396 Number of nonnegative integer matrices with sum of entries equal to 2n or 2n+1, no zero rows or columns, which are symmetric about both diagonals.

Table of values

List of values

cp's OEIS Frontend

A370396 Number of nonnegative integer matrices with sum of entries equal to 2*n or 2*n+1, no zero rows or columns, which are symmetric about both diagonals.

Table of values

List of values

A370396 Number of nonnegative integer matrices with sum of entries equal to 2n or 2n+1, no zero rows or columns, which are symmetric about both diagonals.