A116646 - cp's OEIS frontend

A116646 Number of doubletons in all partitions of n. By a doubleton in a partition we mean an occurrence of a part exactly twice (the partition [4,(3,3),2,2,2,(1,1)] has two doubletons, shown between parentheses).

n	a(n)
0	0
1	0
2	1
3	0
4	2
5	2
6	4
7	5
8	10
9	11
10	20
11	25
12	38
13	49
14	73
15	91
16	131
17	167
18	228
19	291
20	392
21	493
22	653
23	822
24	1065
25	1336
26	1714
27	2131
28	2706
29	3354
30	4209
31	5193
32	6471
33	7934
34	9817
35	11990
36	14725
37	17909
38	21875
39	26477
40	32172
41	38797
42	46893
43	56339
44	67804
45	81147
46	97260
47	116017

[0, 0, 1, 0, 2, 2, 4, 5, 10, 11, 20, 25, 38, 49, 73, 91, 131, 167, 228, 291, 392, 493, 653, 822, 1065, 1336, 1714, 2131, 2706, 3354, 4209, 5193, 6471, 7934, 9817, 11990, 14725, 17909, 21875, 26477, 32172, 38797, 46893, 56339, 67804, 81147, 97260, 116017]

cp's OEIS Frontend

A116646 Number of doubletons in all partitions of n. By a doubleton in a partition we mean an occurrence of a part exactly twice (the partition [4,(3,3),2,2,2,(1,1)] has two doubletons, shown between parentheses).

Table of values

List of values