A358560 - cp's OEIS frontend

A358560 a(n) = Sum_{k=0..floor(n/3)} (n-k)!/(k! * (n-3*k)!).

n	a(n)
0	1
1	1
2	1
3	3
4	7
5	13
6	33
7	91
8	223
9	597
10	1753
11	4963
12	14391
13	44413
14	137137
15	427083
16	1382383
17	4534981
18	14981673
19	50719507
20	174494983
21	605276973
22	2135204161
23	7647369403
24	27643067007
25	101211363253
26	375548195833
27	1406858084931
28	5326762882903
29	20403498329437

[1, 1, 1, 3, 7, 13, 33, 91, 223, 597, 1753, 4963, 14391, 44413, 137137, 427083, 1382383, 4534981, 14981673, 50719507, 174494983, 605276973, 2135204161, 7647369403, 27643067007, 101211363253, 375548195833, 1406858084931, 5326762882903, 20403498329437]

cp's OEIS Frontend

A358560 a(n) = Sum_{k=0..floor(n/3)} (n-k)!/(k! * (n-3*k)!).

Table of values

List of values