Number of 2-step self-avoiding walks on an n X n X n X n 4-cube summed over all starting positions.

Terms

a(0) =0a(1) =64a(2) =432a(3) =1536a(4) =4000a(5) =8640a(6) =16464a(7) =28672a(8) =46656a(9) =72000a(10) =106480a(11) =152064a(12) =210912a(13) =285376a(14) =378000a(15) =491520a(16) =628864a(17) =793152a(18) =987696a(19) =1216000a(20) =1481760a(21) =1788864a(22) =2141392a(23) =2543616a(24) =3000000a(25) =3515200a(26) =4094064a(27) =4741632a(28) =5463136a(29) =6264000