Numbers k such that k - sopfr(k) is a positive fourth power.

Terms

a(0) =1a(1) =6a(2) =166a(3) =650a(4) =4125a(5) =4476a(6) =13126a(7) =28866a(8) =50721a(9) =101254a(10) =194680a(11) =194691a(12) =197631a(13) =388966a(14) =391874a(15) =392245a(16) =401796a(17) =883644a(18) =933058a(19) =1051146a(20) =1212885a(21) =1338556a(22) =1345468a(23) =1362556a(24) =3112095a(25) =3112338a(26) =3229448a(27) =3429816a(28) =3748206a(29) =3907208