A subsequence of the denominators of the Bernoulli numbers: a(n) = A027642(A131577(n)).

Terms

a(0) =1a(1) =2a(2) =6a(3) =30a(4) =30a(5) =510a(6) =510a(7) =510a(8) =510a(9) =131070a(10) =131070a(11) =131070a(12) =131070a(13) =131070a(14) =131070a(15) =131070a(16) =131070a(17) =8589934590a(18) =8589934590a(19) =8589934590a(20) =8589934590a(21) =8589934590a(22) =8589934590a(23) =8589934590a(24) =8589934590a(25) =8589934590a(26) =8589934590a(27) =8589934590a(28) =8589934590a(29) =8589934590