Fourth right hand column of triangle A163940.

Terms

a(0) =1a(1) =9a(2) =52a(3) =246a(4) =1039a(5) =4083a(6) =15274a(7) =55152a(8) =193957a(9) =668397a(10) =2266816a(11) =7589418a(12) =25143355a(13) =82571751a(14) =269173078a(15) =871958244a(16) =2809322833a(17) =9008574945a(18) =28768068460a(19) =91532284830a(20) =290283189991a(21) =917912770779