A001609 - cp's OEIS frontend

A001609 a(1) = a(2) = 1, a(3) = 4; thereafter a(n) = a(n-1) + a(n-3).

n	a(n)
1	1
2	1
3	4
4	5
5	6
6	10
7	15
8	21
9	31
10	46
11	67
12	98
13	144
14	211
15	309
16	453
17	664
18	973
19	1426
20	2090
21	3063
22	4489
23	6579
24	9642
25	14131
26	20710
27	30352
28	44483
29	65193
30	95545
31	140028
32	205221
33	300766
34	440794
35	646015
36	946781
37	1387575
38	2033590
39	2980371
40	4367946
41	6401536
42	9381907

[1, 1, 4, 5, 6, 10, 15, 21, 31, 46, 67, 98, 144, 211, 309, 453, 664, 973, 1426, 2090, 3063, 4489, 6579, 9642, 14131, 20710, 30352, 44483, 65193, 95545, 140028, 205221, 300766, 440794, 646015, 946781, 1387575, 2033590, 2980371, 4367946, 6401536, 9381907]

cp's OEIS Frontend

A001609 a(1) = a(2) = 1, a(3) = 4; thereafter a(n) = a(n-1) + a(n-3).

Table of values

List of values