Numbers k such that k' = concat(s,t) and k = s*t, where k' is the arithmetic derivative of k.

Terms

a(0) =648a(1) =750a(2) =4050a(3) =35574a(4) =50000a(5) =85440a(6) =87500a(7) =105984a(8) =183141a(9) =193750a(10) =213759a(11) =223600a(12) =290625a(13) =297500a(14) =332000a(15) =368550a(16) =468750a(17) =473000a(18) =479600a(19) =484375a(20) =511584a(21) =520625a(22) =529984a(23) =531050a(24) =678125a(25) =754392a(26) =825000a(27) =987500a(28) =999840a(29) =1011375