A276735 - cp's OEIS frontend

A276735 Number of permutations p of (1..n) such that k+p(k) is a semiprime for 1 <= k <= n.

n	a(n)
0	1
1	0
2	0
3	1
4	1
5	3
6	5
7	12
8	87
9	261
10	324
11	1433
12	5881
13	37444
14	196797
15	708901
16	2020836
17	12375966
18	105896734
19	955344450
20	11136621319
21	95274505723
22	590283352231
23	4285001635230
24	36417581252044
25	272699023606314

[1, 0, 0, 1, 1, 3, 5, 12, 87, 261, 324, 1433, 5881, 37444, 196797, 708901, 2020836, 12375966, 105896734, 955344450, 11136621319, 95274505723, 590283352231, 4285001635230, 36417581252044, 272699023606314]

cp's OEIS Frontend

A276735 Number of permutations p of (1..n) such that k+p(k) is a semiprime for 1 <= k <= n.

Table of values

List of values