A371872 - cp's OEIS frontend

A371872 a(n) = Sum_{k=0..floor(n/3)} binomial(2n-2k-1,n-3*k).

n	a(n)
0	1
1	1
2	3
3	11
4	40
5	147
6	547
7	2055
8	7777
9	29602
10	113204
11	434591
12	1673821
13	6464539
14	25026534
15	97087873
16	377329971
17	1468856383
18	5726159811
19	22351657810
20	87350137071
21	341726039806
22	1338173763288
23	5244830032639
24	20573285744475
25	80761011408961
26	317249771957040

[1, 1, 3, 11, 40, 147, 547, 2055, 7777, 29602, 113204, 434591, 1673821, 6464539, 25026534, 97087873, 377329971, 1468856383, 5726159811, 22351657810, 87350137071, 341726039806, 1338173763288, 5244830032639, 20573285744475, 80761011408961, 317249771957040]

cp's OEIS Frontend

A371872 a(n) = Sum_{k=0..floor(n/3)} binomial(2n-2k-1,n-3*k).

Table of values

List of values

cp's OEIS Frontend

A371872 a(n) = Sum_{k=0..floor(n/3)} binomial(2*n-2*k-1,n-3*k).

Table of values

List of values

A371872 a(n) = Sum_{k=0..floor(n/3)} binomial(2n-2k-1,n-3*k).