A118928 - cp's OEIS frontend

A118928 a(n) = Sum_{k=0..floor(n/2)} C(n-k,k)C(n-k,k+1)/(n-k) a(k), with a(0)=1.

n	a(n)
0	1
1	1
2	1
3	2
4	4
5	8
6	17
7	38
8	92
9	238
10	643
11	1790
12	5076
13	14573
14	42241
15	123484
16	364052
17	1082602
18	3247759
19	9829820
20	30019326
21	92517644
22	287805801
23	903822922
24	2865339252
25	9168572009
26	29601077285
27	96377791839
28	316264456921

[1, 1, 1, 2, 4, 8, 17, 38, 92, 238, 643, 1790, 5076, 14573, 42241, 123484, 364052, 1082602, 3247759, 9829820, 30019326, 92517644, 287805801, 903822922, 2865339252, 9168572009, 29601077285, 96377791839, 316264456921]

cp's OEIS Frontend

A118928 a(n) = Sum_{k=0..floor(n/2)} C(n-k,k)C(n-k,k+1)/(n-k) a(k), with a(0)=1.

Table of values

List of values

cp's OEIS Frontend

A118928 a(n) = Sum_{k=0..floor(n/2)} C(n-k,k)*C(n-k,k+1)/(n-k) * a(k), with a(0)=1.

Table of values

List of values

A118928 a(n) = Sum_{k=0..floor(n/2)} C(n-k,k)C(n-k,k+1)/(n-k) a(k), with a(0)=1.