A133305 - cp's OEIS frontend

A133305 a(n) = (1/n)Sum_{i=0..n-1} C(n,i)C(n,i+1)4^i5^(n-i), a(0) = 1.

n	a(n)
0	1
1	5
2	45
3	505
4	6345
5	85405
6	1204245
7	17558705
8	262577745
9	4005148405
10	62070886845
11	974612606505
12	15471084667545
13	247876665109005
14	4003225107031845
15	65101209768055905
16	1065128963164067745
17	17520376884067071205
18	289572455530026439245
19	4806489064223483202905

[1, 5, 45, 505, 6345, 85405, 1204245, 17558705, 262577745, 4005148405, 62070886845, 974612606505, 15471084667545, 247876665109005, 4003225107031845, 65101209768055905, 1065128963164067745, 17520376884067071205, 289572455530026439245, 4806489064223483202905]

cp's OEIS Frontend

A133305 a(n) = (1/n)Sum_{i=0..n-1} C(n,i)C(n,i+1)4^i5^(n-i), a(0) = 1.

Table of values

List of values

cp's OEIS Frontend

A133305 a(n) = (1/n)*Sum_{i=0..n-1} C(n,i)*C(n,i+1)*4^i*5^(n-i), a(0) = 1.

Table of values

List of values

A133305 a(n) = (1/n)Sum_{i=0..n-1} C(n,i)C(n,i+1)4^i5^(n-i), a(0) = 1.