Number of circular permutations of 1..n with no adjacent three summing to a prime, ignoring rotations and reversals.
A212268
Number of circular permutations of 1..n with no adjacent three summing to a prime, ignoring rotations and reversals.
Terms
- a(0) =0a(1) =0a(2) =1a(3) =0a(4) =2a(5) =4a(6) =14a(7) =48a(8) =432a(9) =2316a(10) =24743a(11) =223506a(12) =2537594a(13) =26771235a(14) =344781871a(15) =3927465497a(16) =53273396228a(17) =660418431957
External references
- oeis: A212268