Number of 3-step king's tours on an n X n board summed over all starting positions.

Terms

a(0) =0a(1) =24a(2) =160a(3) =408a(4) =768a(5) =1240a(6) =1824a(7) =2520a(8) =3328a(9) =4248a(10) =5280a(11) =6424a(12) =7680a(13) =9048a(14) =10528a(15) =12120a(16) =13824a(17) =15640a(18) =17568a(19) =19608a(20) =21760a(21) =24024a(22) =26400a(23) =28888a(24) =31488a(25) =34200a(26) =37024a(27) =39960a(28) =43008a(29) =46168