a(n) = binomial(s(n), n) where s(n) = n-th semiprime.

A117927

a(n) = binomial(s(n), n) where s(n) = n-th semiprime.

Terms

    a(0) =4a(1) =15a(2) =84a(3) =210a(4) =2002a(5) =5005a(6) =116280a(7) =319770a(8) =2042975a(9) =5311735a(10) =193536720a(11) =548354040a(12) =1476337800a(13) =9669554100a(14) =25140840660a(15) =991493848554

External references