Number of ways of arranging the numbers 1 through n on a circle so that no sum of two adjacent numbers is prime, up to rotations and reflections.
A182540
Number of ways of arranging the numbers 1 through n on a circle so that no sum of two adjacent numbers is prime, up to rotations and reflections.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =6a(7) =44a(8) =208a(9) =912a(10) =8016a(11) =61952a(12) =671248a(13) =8160620a(14) =87412258a(15) =888954284a(16) =12156253488a(17) =180955852060
External references
- oeis: A182540