A358547 - cp's OEIS frontend

A358547 a(n) = Sum_{k=0..floor(n/3)} (n-k)!/(n-3*k)!.

n	a(n)
0	1
1	1
2	1
3	3
4	7
5	13
6	45
7	151
8	403
9	1617
10	6793
11	23275
12	105951
13	522133
14	2159077
15	10964223
16	61134955
17	293587801
18	1641566913
19	10124731987
20	55014334903
21	335177088285
22	2251814156701
23	13587321392743
24	89436553249347
25	647267633012833
26	4276528756374265
27	30198747030078651

[1, 1, 1, 3, 7, 13, 45, 151, 403, 1617, 6793, 23275, 105951, 522133, 2159077, 10964223, 61134955, 293587801, 1641566913, 10124731987, 55014334903, 335177088285, 2251814156701, 13587321392743, 89436553249347, 647267633012833, 4276528756374265, 30198747030078651]

cp's OEIS Frontend

A358547 a(n) = Sum_{k=0..floor(n/3)} (n-k)!/(n-3*k)!.

Table of values

List of values