Number of 7-step king's tours on an n X n board summed over all starting positions.

Terms

a(0) =0a(1) =0a(2) =2984a(3) =68272a(4) =296360a(5) =722384a(6) =1335984a(7) =2129440a(8) =3102752a(9) =4255920a(10) =5588944a(11) =7101824a(12) =8794560a(13) =10667152a(14) =12719600a(15) =14951904a(16) =17364064a(17) =19956080a(18) =22727952a(19) =25679680a(20) =28811264a(21) =32122704a(22) =35614000a(23) =39285152a(24) =43136160a(25) =47167024