Least positive integer k for which 5^n divides k!.

Terms

a(0) =1a(1) =5a(2) =10a(3) =15a(4) =20a(5) =25a(6) =25a(7) =30a(8) =35a(9) =40a(10) =45a(11) =50a(12) =50a(13) =55a(14) =60a(15) =65a(16) =70a(17) =75a(18) =75a(19) =80a(20) =85a(21) =90a(22) =95a(23) =100a(24) =100a(25) =105a(26) =110a(27) =115a(28) =120a(29) =125