Generalized Bell numbers.

Terms

a(0) =0a(1) =4a(2) =27a(3) =172a(4) =1125a(5) =7591a(6) =52479a(7) =369580a(8) =2640465a(9) =19082629a(10) =139207959a(11) =1023462199a(12) =7574172879a(13) =56369211679a(14) =421563478527