A373719 - cp's OEIS frontend

A373719 a(n) = Sum_{k=0..floor(n^2/(2n+1))} binomial(n (n-2*k),k).

n	a(n)
0	1
1	1
2	1
3	4
4	9
5	26
6	91
7	281
8	1105
9	4105
10	16576
11	70643
12	301405
13	1382928
14	6363876
15	30605836
16	150820769
17	758835104
18	3941917840
19	20787546715
20	112615930451
21	620969188400
22	3492709446326
23	20034747631656
24	116780977502105
25	693539635192626
26	4181549476945504
27	25627647913369903

[1, 1, 1, 4, 9, 26, 91, 281, 1105, 4105, 16576, 70643, 301405, 1382928, 6363876, 30605836, 150820769, 758835104, 3941917840, 20787546715, 112615930451, 620969188400, 3492709446326, 20034747631656, 116780977502105, 693539635192626, 4181549476945504, 25627647913369903]

cp's OEIS Frontend

A373719 a(n) = Sum_{k=0..floor(n^2/(2n+1))} binomial(n (n-2*k),k).

Table of values

List of values

cp's OEIS Frontend

A373719 a(n) = Sum_{k=0..floor(n^2/(2*n+1))} binomial(n * (n-2*k),k).

Table of values

List of values

A373719 a(n) = Sum_{k=0..floor(n^2/(2n+1))} binomial(n (n-2*k),k).