Number of circular permutations i_0, i_1, ..., i_n of 0, 1, ..., n such that all the n+1 numbers i_0^2+i_1, i_1^2+i_2, ..., i_{n-1}^2+i_n, i_n^2+i_0 are of the form (p-1)/2 with p an odd prime.
A229082
Number of circular permutations i_0, i_1, ..., i_n of 0, 1, ..., n such that all the n+1 numbers i_0^2+i_1, i_1^2+i_2, ..., i_{n-1}^2+i_n, i_n^2+i_0 are of the form (p-1)/2 with p an odd prime.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =0a(4) =2a(5) =3a(6) =7a(7) =11a(8) =9a(9) =5a(10) =41a(11) =82a(12) =254a(13) =2412a(14) =9524a(15) =13925a(16) =85318a(17) =220818a(18) =1662421a(19) =10496784a(20) =20690118a(21) =97200566a(22) =460358077
External references
- oeis: A229082