Number of 9-step self-avoiding walks on an n X n square summed over all starting positions.

Terms

a(0) =0a(1) =0a(2) =40a(3) =2640a(4) =14520a(5) =39792a(6) =78168a(7) =128688a(8) =191068a(9) =265280a(10) =351324a(11) =449200a(12) =558908a(13) =680448a(14) =813820a(15) =959024a(16) =1116060a(17) =1284928a(18) =1465628a(19) =1658160a(20) =1862524a(21) =2078720a(22) =2306748a(23) =2546608a(24) =2798300a(25) =3061824a(26) =3337180a(27) =3624368a(28) =3923388a(29) =4234240