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

Terms

a(0) =0a(1) =8a(2) =80a(3) =232a(4) =456a(5) =752a(6) =1120a(7) =1560a(8) =2072a(9) =2656a(10) =3312a(11) =4040a(12) =4840a(13) =5712a(14) =6656a(15) =7672a(16) =8760a(17) =9920a(18) =11152a(19) =12456a(20) =13832a(21) =15280a(22) =16800a(23) =18392a(24) =20056a(25) =21792a(26) =23600a(27) =25480a(28) =27432a(29) =29456