A073451 - cp's OEIS frontend

A073451 Number of essentially different ways in which the squares 1,4,9,...,n^2 can be arranged in a sequence such that all pairs of adjacent squares 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	4
7	0
8	12
9	6
10	66
11	156
12	44
13	312
14	1484
15	2672
16	6680
17	19080
18	45024
19	168496
20	2033271
21	724543
22	2776536
23	24598062
24	26849699
25	345160845
26	4478968678
27	5094833662
28	14184530127
29	29116554754
30	125878922175

[1, 1, 1, 1, 2, 4, 0, 12, 6, 66, 156, 44, 312, 1484, 2672, 6680, 19080, 45024, 168496, 2033271, 724543, 2776536, 24598062, 26849699, 345160845, 4478968678, 5094833662, 14184530127, 29116554754, 125878922175]

cp's OEIS Frontend

A073451 Number of essentially different ways in which the squares 1,4,9,...,n^2 can be arranged in a sequence such that all pairs of adjacent squares sum to a prime number. Rotations and reversals are counted only once.

Table of values

List of values