Guttmann-Torrie series coefficients c_{n}^{21} for square lattice, with wedge angle Pi/4.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =8a(6) =15a(7) =31a(8) =66a(9) =142a(10) =306a(11) =678a(12) =1512a(13) =3410a(14) =7750a(15) =17786a(16) =41067a(17) =95514a(18) =223295a(19) =525203a(20) =1240734a(21) =2945383a(22) =7019239a(23) =16795983a(24) =40325120a(25) =97153672a(26) =234753693a(27) =568950192