Numbers k such that sigma(k) - tau(k) is a prime.

Terms

a(0) =3a(1) =8a(2) =162a(3) =512a(4) =1250a(5) =8192a(6) =31250a(7) =32768a(8) =41472a(9) =663552a(10) =2531250a(11) =3748322a(12) =5120000a(13) =6837602a(14) =7558272a(15) =8000000a(16) =15780962a(17) =33554432a(18) =35701250a(19) =42762752a(20) =45334242a(21) =68024448a(22) =75031250a(23) =78125000a(24) =91125000a(25) =137149922a(26) =243101250a(27) =512000000a(28) =907039232a(29) =959570432