Second column of A027516.

Terms

a(0) =1a(1) =5a(2) =26a(3) =247a(4) =2971a(5) =11729a(6) =17212a(7) =22396a(8) =30830a(9) =157265a(10) =210937a(11) =13364063a(12) =311800655a(13) =779670085a(14) =991056257a(15) =610968694a(16) =1532109175a(17) =13111582397a(18) =308183411213a(19) =374393615461