A371785 - cp's OEIS frontend

A371785 a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(3n-k,n-2k).

n	a(n)
0	1
1	3
2	14
3	76
4	441
5	2652
6	16303
7	101727
8	641630
9	4080154
10	26112384
11	167978615
12	1085182436
13	7035477777
14	45750406205
15	298279844724
16	1949096816505
17	12761551428024
18	83701819019155
19	549850618355886
20	3617119500327536
21	23824816811652905
22	157106267803712709

[1, 3, 14, 76, 441, 2652, 16303, 101727, 641630, 4080154, 26112384, 167978615, 1085182436, 7035477777, 45750406205, 298279844724, 1949096816505, 12761551428024, 83701819019155, 549850618355886, 3617119500327536, 23824816811652905, 157106267803712709]

cp's OEIS Frontend

A371785 a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(3n-k,n-2k).

Table of values

List of values

cp's OEIS Frontend

A371785 a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(3*n-k,n-2*k).

Table of values

List of values

A371785 a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(3n-k,n-2k).