Number of ways to partition an n X 3 grid into 3 connected equal-area regions.

Terms

a(0) =1a(1) =3a(2) =10a(3) =23a(4) =56a(5) =132a(6) =259a(7) =546a(8) =1095a(9) =2043a(10) =3908a(11) =7379a(12) =13208a(13) =24194a(14) =43819a(15) =76790a(16) =136489a(17) =241311a(18) =416152a(19) =726073a(20) =1261696a(21) =2153026a(22) =3706393a(23) =6364842a(24) =10775173a(25) =18374181