a(n) is the smallest number m such that the sum of the first m squares ends in n '0's.

A174245

a(n) is the smallest number m such that the sum of the first m squares ends in n '0's.

Terms

    a(0) =4a(1) =24a(2) =624a(3) =5312a(4) =45312a(5) =445312a(6) =6445312a(7) =12890624a(8) =212890624a(9) =893554687a(10) =40893554687a(11) =40893554687a(12) =81787109375

External references