Ceiling of Gamma(n+1/2)/Gamma(1/2).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =7a(5) =30a(6) =163a(7) =1056a(8) =7919a(9) =67304a(10) =639384a(11) =6713531a(12) =77205602a(13) =965070018a(14) =13028445232a(15) =188912455861