Numbers x such that x = concatenate(a, b) and phi(a) + phi(b) = sigma(x) - x.

Terms

a(0) =49a(1) =169a(2) =289a(3) =611a(4) =1751a(5) =2171a(6) =2231a(7) =7921a(8) =10751a(9) =11479a(10) =23153a(11) =24367a(12) =38551a(13) =38809a(14) =49901a(15) =99101a(16) =116303a(17) =143351a(18) =229441a(19) =268151a(20) =271441a(21) =306181a(22) =357101a(23) =1030301a(24) =2014751a(25) =2078663