Cubefree part of n!.

Terms

a(0) =1a(1) =2a(2) =6a(3) =3a(4) =15a(5) =90a(6) =630a(7) =630a(8) =210a(9) =2100a(10) =23100a(11) =34650a(12) =450450a(13) =6306300a(14) =28028a(15) =7007a(16) =119119a(17) =2144142a(18) =40738698a(19) =101846745a(20) =230945a(21) =5080790a(22) =116858170a(23) =350574510a(24) =70114902a(25) =1822987452a(26) =1822987452a(27) =6380456082a(28) =185033226378