Minimum solution for tri-color tower of Hanoi, restricted so like colors can't be together.

Terms

a(0) =1a(1) =3a(2) =7a(3) =19a(4) =43a(5) =99a(6) =235a(7) =535a(8) =1239a(9) =2879a(10) =6619a(11) =15323a(12) =35451a(13) =81823a(14) =189263a(15) =437543a(16) =1011059a(17) =2337731a(18) =5403987a(19) =12491223a(20) =28877687a(21) =66755519a(22) =154315883a(23) =356738411a(24) =824668747a(25) =1906384015a(26) =4407016991a(27) =10187707927a(28) =23550975203