Binomial transform of A026007.

Terms

a(0) =1a(1) =2a(2) =5a(3) =15a(4) =45a(5) =132a(6) =381a(7) =1086a(8) =3060a(9) =8531a(10) =23563a(11) =64560a(12) =175639a(13) =474790a(14) =1275929a(15) =3410180a(16) =9068075a(17) =23998671a(18) =63230680a(19) =165904474a(20) =433596795a(21) =1129037237a(22) =2929620046a(23) =7576584801a(24) =19532878559a(25) =50205938903a(26) =128676829149a(27) =328895341731a(28) =838453003422