Number of undirected circular permutations i_0, i_1, ..., i_n of 0, 1, ..., n such that all the n+1 adjacent distances |i_0-i_1|, |i_1-i_2|, ..., |i_{n-1}-i_n|, |i_n-i_0| are perfect squares.

A229543

Number of undirected circular permutations i_0, i_1, ..., i_n of 0, 1, ..., n such that all the n+1 adjacent distances |i_0-i_1|, |i_1-i_2|, ..., |i_{n-1}-i_n|, |i_n-i_0| are perfect squares.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =1a(4) =0a(5) =1a(6) =1a(7) =1a(8) =9a(9) =14a(10) =32a(11) =184a(12) =123a(13) =696a(14) =935a(15) =6554a(16) =21105a(17) =60756a(18) =241780a(19) =517970a(20) =1835109a(21) =5741024a(22) =16091004a(23) =63590090a(24) =285113492a(25) =1098219807

External references