Number of n-step self-avoiding walks on the square lattice with first step specified.

Terms

a(0) =1a(1) =3a(2) =9a(3) =25a(4) =71a(5) =195a(6) =543a(7) =1479a(8) =4067a(9) =11025a(10) =30073a(11) =81233a(12) =220375a(13) =593611a(14) =1604149a(15) =4311333a(16) =11616669a(17) =31164683a(18) =83779155a(19) =224424291a(20) =602201507a(21) =1611140121a(22) =4316653453a(23) =11536599329a(24) =30870338727a(25) =82428196555a(26) =220329372907