A278618 - cp's OEIS frontend

A278618 a(n) = Sum_{j=0..n/2} binomial(n-j-1,n-2j)binomial(2*n+1,j).

n	a(n)
0	1
1	0
2	5
3	7
4	45
5	121
6	533
7	1800
8	7157
9	26239
10	101640
11	384583
12	1483925
13	5693247
14	22013059
15	85076183
16	330014421
17	1281349195
18	4985766650
19	19422653367
20	75775163028
21	295953650376
22	1157212653030
23	4529183513913
24	17743019073381
25	69565441895001

[1, 0, 5, 7, 45, 121, 533, 1800, 7157, 26239, 101640, 384583, 1483925, 5693247, 22013059, 85076183, 330014421, 1281349195, 4985766650, 19422653367, 75775163028, 295953650376, 1157212653030, 4529183513913, 17743019073381, 69565441895001]

cp's OEIS Frontend

A278618 a(n) = Sum_{j=0..n/2} binomial(n-j-1,n-2j)binomial(2*n+1,j).

Table of values

List of values

cp's OEIS Frontend

A278618 a(n) = Sum_{j=0..n/2} binomial(n-j-1,n-2*j)*binomial(2*n+1,j).

Table of values

List of values

A278618 a(n) = Sum_{j=0..n/2} binomial(n-j-1,n-2j)binomial(2*n+1,j).