A124197 - cp's OEIS frontend

A124197 Number of subsets S of {1,2,3,...,n}, including the empty subset, such that if x and y are in S with x and x+y even, then (x+y)/2 is also in S.

n	a(n)
0	1
1	2
2	4
3	7
4	12
5	18
6	26
7	36
8	48
9	61
10	77
11	95
12	115
13	137
14	161
15	187
16	217
17	248
18	281
19	317
20	355
21	395
22	439
23	485
24	533
25	583
26	636
27	691
28	750
29	811
30	874
31	941
32	1010
33	1080
34	1154
35	1230
36	1310
37	1393
38	1478
39	1565
40	1656
41	1749
42	1844
43	1943
44	2044
45	2147
46	2256
47	2367
48	2480
49	2595
50	2713
51	2834

[1, 2, 4, 7, 12, 18, 26, 36, 48, 61, 77, 95, 115, 137, 161, 187, 217, 248, 281, 317, 355, 395, 439, 485, 533, 583, 636, 691, 750, 811, 874, 941, 1010, 1080, 1154, 1230, 1310, 1393, 1478, 1565, 1656, 1749, 1844, 1943, 2044, 2147, 2256, 2367, 2480, 2595, 2713, 2834]

cp's OEIS Frontend

A124197 Number of subsets S of {1,2,3,...,n}, including the empty subset, such that if x and y are in S with x and x+y even, then (x+y)/2 is also in S.

Table of values

List of values