Coordination sequence for C_9 lattice.

Terms

a(0) =1a(1) =162a(2) =4482a(3) =53154a(4) =374274a(5) =1854882a(6) =7159170a(7) =22952610a(8) =63821826a(9) =158611106a(10) =360027522a(11) =758497698a(12) =1501390338a(13) =2818849698a(14) =5057616258a(15) =8724341922a(16) =14540038146a(17) =23507426466a(18) =36993091970a(19) =56826471330a(20) =85417838082a(21) =125897578914a(22) =182279185794a(23) =259648519842