Number of 8-step king's tours on an n X n board summed over all starting positions.

Terms

a(0) =0a(1) =0a(2) =2384a(3) =183472a(4) =1110000a(5) =3193800a(6) =6481216a(7) =10899404a(8) =16418600a(9) =23038804a(10) =30760016a(11) =39582236a(12) =49505464a(13) =60529700a(14) =72654944a(15) =85881196a(16) =100208456a(17) =115636724a(18) =132166000a(19) =149796284a(20) =168527576a(21) =188359876a(22) =209293184a(23) =231327500a(24) =254462824a(25) =278699156