A073452 - cp's OEIS frontend

A073452 a(n) is the number of essentially different ways in which the integers 1,2,3,...,n can be arranged in a sequence such that all pairs of adjacent integers sum to a prime number. Rotations and reversals are counted only once.

n	a(n)
1	1
2	1
3	1
4	1
5	2
6	3
7	12
8	16
9	70
10	232
11	1072
12	3136
13	11648
14	18388
15	95772
16	452136
17	2047488
18	5565488
19	22802028
20	60841609
21	337801784
22	2116714332
23	11425028900
24	69023494710
25	429917269469

[1, 1, 1, 1, 2, 3, 12, 16, 70, 232, 1072, 3136, 11648, 18388, 95772, 452136, 2047488, 5565488, 22802028, 60841609, 337801784, 2116714332, 11425028900, 69023494710, 429917269469]

cp's OEIS Frontend

A073452 a(n) is the number of essentially different ways in which the integers 1,2,3,...,n can be arranged in a sequence such that all pairs of adjacent integers sum to a prime number. Rotations and reversals are counted only once.

Table of values

List of values