A327999 - cp's OEIS frontend

A327999 a(n) = Sum_{k=0..2n}(k!(2n - k)!)/(floor(k/2)!floor((2n - k)/2)!)^2.

n	a(n)
0	1
1	5
2	28
3	160
4	896
5	4864
6	25600
7	131072
8	655360
9	3211264
10	15466496
11	73400320
12	343932928
13	1593835520
14	7314866176
15	33285996544
16	150323855360
17	674309865472
18	3006477107200
19	13331578486784
20	58823872086016
21	258385232527360
22	1130297953353728
23	4925812092436480

[1, 5, 28, 160, 896, 4864, 25600, 131072, 655360, 3211264, 15466496, 73400320, 343932928, 1593835520, 7314866176, 33285996544, 150323855360, 674309865472, 3006477107200, 13331578486784, 58823872086016, 258385232527360, 1130297953353728, 4925812092436480]

cp's OEIS Frontend

A327999 a(n) = Sum_{k=0..2n}(k!(2n - k)!)/(floor(k/2)!floor((2n - k)/2)!)^2.

Table of values

List of values

cp's OEIS Frontend

A327999 a(n) = Sum_{k=0..2n}(k!*(2n - k)!)/(floor(k/2)!*floor((2n - k)/2)!)^2.

Table of values

List of values

A327999 a(n) = Sum_{k=0..2n}(k!(2n - k)!)/(floor(k/2)!floor((2n - k)/2)!)^2.