Numerator of n^(n-2)/n!.

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =25a(5) =9a(6) =2401a(7) =2048a(8) =59049a(9) =15625a(10) =214358881a(11) =248832a(12) =137858491849a(13) =564950498a(14) =21357421875a(17) =282429536481