Number of permutations i_0, i_1, ..., i_n of 0, 1, ..., n with i_0 = 0 and i_n = n such that 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 all relatively prime to both n-1 and n+1.

A229130

Number of permutations i_0, i_1, ..., i_n of 0, 1, ..., n with i_0 = 0 and i_n = n such that 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 all relatively prime to both n-1 and n+1.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =1a(4) =0a(5) =6a(6) =3a(7) =42a(8) =68a(9) =2794a(10) =0a(11) =5311604a(12) =478a(13) =57009a(14) =2716452a(15) =10778632a(16) =207360a(18) =106144a(19) =26869397610a(20) =11775466120a(22) =559350576a(24) =257272815600

External references