Numbers k such that (k + k')' = k' + k'', where ' denotes the arithmetic derivative A003415.

Terms

a(0) =1a(1) =2a(2) =16a(3) =98a(4) =108a(5) =275a(6) =598a(7) =729a(8) =2419a(9) =3503a(10) =5324a(11) =11304a(12) =12500a(13) =35937a(14) =50498a(15) =51179a(16) =58339a(17) =76302a(18) =84375a(19) =107830a(20) =141775a(21) =209663a(22) =324480a(23) =588800a(24) =618434a(25) =1090123a(26) =1532188a(27) =2190240a(28) =2615251a(29) =3175699