A379086 - cp's OEIS frontend

A379086 a(n) = Sum_{k=0..floor(n/2)} binomial(3n+k-1,k) binomial(3n+k,n-2k).

n	a(n)
0	1
1	3
2	21
3	174
4	1509
5	13443
6	121962
7	1120899
8	10401021
9	97230090
10	914283621
11	8638552464
12	81945757734
13	779949538176
14	7444735446813
15	71237074583589
16	683125330952205
17	6563268117869076
18	63164380112090814
19	608805362150884731
20	5875874727915635409
21	56780302474503539427
22	549294315060885105744

[1, 3, 21, 174, 1509, 13443, 121962, 1120899, 10401021, 97230090, 914283621, 8638552464, 81945757734, 779949538176, 7444735446813, 71237074583589, 683125330952205, 6563268117869076, 63164380112090814, 608805362150884731, 5875874727915635409, 56780302474503539427, 549294315060885105744]

cp's OEIS Frontend

A379086 a(n) = Sum_{k=0..floor(n/2)} binomial(3n+k-1,k) binomial(3n+k,n-2k).

Table of values

List of values

cp's OEIS Frontend

A379086 a(n) = Sum_{k=0..floor(n/2)} binomial(3*n+k-1,k) * binomial(3*n+k,n-2*k).

Table of values

List of values

A379086 a(n) = Sum_{k=0..floor(n/2)} binomial(3n+k-1,k) binomial(3n+k,n-2k).