[math-fun] Re: some puzzle sequences not in OEIS!

17: 36, 864, 21060, 544320, ? If we index starting at 1, we have a(n) = a(n-1) ((n+10)(9n-12)/(5n-7)). This gives ? = 14968800. However, the subsequent term is noninteger. Yeah, it's ugly, what can I say.