Denominator of the fraction c(n) defined in A172030.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =3a(5) =30a(6) =15a(7) =70a(8) =35a(9) =210a(10) =105a(11) =2310a(12) =1155a(13) =10010a(14) =5005a(15) =30030a(16) =15015a(17) =510510a(18) =255255a(19) =3233230a(20) =1616615a(21) =1939938a(22) =969969a(23) =44618574a(24) =22309287a(25) =74364290a(26) =37182145a(27) =223092870a(28) =111546435a(29) =6469693230