a(n) is the smallest number m such that the m-th triangular number ends in n zeros.

A228191

a(n) is the smallest number m such that the m-th triangular number ends in n zeros.

Terms

    a(0) =4a(1) =24a(2) =624a(3) =9375a(4) =90624a(5) =890624a(6) =7109375a(7) =12890624a(8) =212890624a(9) =1787109375a(10) =81787109375a(11) =81787109375a(12) =81787109375

External references