155625domain: NAppears in sequencesSmallest number m such that m and the product of digits of m are both divisible by 5n, or 0 if no such number exists.at n=74A073911a(n) = Sum_{i=0..n} digsum_7(i)^4, where digsum_7(i) = A053828(i).at n=49A231679Number of ordinary double points of a family of threefolds.at n=23A294604