A328494 - cp's OEIS frontend

A328494 Constant term in the expansion of (1+x+y+1/x+1/y)^n without assuming commutativity.

n	a(n)
0	1
1	1
2	5
3	13
4	53
5	181
6	713
7	2689
8	10661
9	41989
10	168785
11	680329
12	2770409
13	11331529
14	46639157
15	192762013
16	800228069
17	3333843685
18	13936599857
19	58432259977
20	245665962113
21	1035412181761
22	4373982501245
23	18516210906853
24	78536526586553
25	333712398776281
26	1420364536094093

[1, 1, 5, 13, 53, 181, 713, 2689, 10661, 41989, 168785, 680329, 2770409, 11331529, 46639157, 192762013, 800228069, 3333843685, 13936599857, 58432259977, 245665962113, 1035412181761, 4373982501245, 18516210906853, 78536526586553, 333712398776281, 1420364536094093]

cp's OEIS Frontend

A328494 Constant term in the expansion of (1+x+y+1/x+1/y)^n without assuming commutativity.

Table of values

List of values