A371819 - cp's OEIS frontend

A371819 a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2n-k+1,n-3k).

n	a(n)
0	1
1	3
2	10
3	34
4	118
5	417
6	1497
7	5447
8	20047
9	74493
10	279054
11	1052467
12	3992204
13	15216662
14	58239175
15	223688159
16	861769598
17	3328779906
18	12887832493
19	49998248601
20	194315972151
21	756406944446
22	2948649839743
23	11509316352548
24	44976030493706
25	175942932935325

[1, 3, 10, 34, 118, 417, 1497, 5447, 20047, 74493, 279054, 1052467, 3992204, 15216662, 58239175, 223688159, 861769598, 3328779906, 12887832493, 49998248601, 194315972151, 756406944446, 2948649839743, 11509316352548, 44976030493706, 175942932935325]

cp's OEIS Frontend

A371819 a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2n-k+1,n-3k).

Table of values

List of values

cp's OEIS Frontend

A371819 a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2*n-k+1,n-3*k).

Table of values

List of values

A371819 a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2n-k+1,n-3k).