A050228 - cp's OEIS frontend

A050228 a(n) is the number of subsequences {s(k)} of {1,2,3,...n} such that s(k+1)-s(k) is 1 or 3.

n	a(n)
1	1
2	3
3	6
4	11
5	19
6	31
7	49
8	76
9	116
10	175
11	262
12	390
13	578
14	854
15	1259
16	1853
17	2724
18	4001
19	5873
20	8617
21	12639
22	18534
23	27174
24	39837
25	58396
26	85596
27	125460
28	183884
29	269509
30	394999
31	578914
32	848455
33	1243487
34	1822435
35	2670925
36	3914448
37	5736920
38	8407883

[1, 3, 6, 11, 19, 31, 49, 76, 116, 175, 262, 390, 578, 854, 1259, 1853, 2724, 4001, 5873, 8617, 12639, 18534, 27174, 39837, 58396, 85596, 125460, 183884, 269509, 394999, 578914, 848455, 1243487, 1822435, 2670925, 3914448, 5736920, 8407883]

cp's OEIS Frontend

A050228 a(n) is the number of subsequences {s(k)} of {1,2,3,...n} such that s(k+1)-s(k) is 1 or 3.

Table of values

List of values