Nearest integer to Gamma(n+2/3).

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =15a(5) =69a(6) =389a(7) =2594a(8) =19884a(9) =172328a(10) =1665838a(11) =17768938a(12) =207304278a(13) =2625854188a(14) =35886673906a(15) =526337883960