Numbers k such that k^2 + sopfr(k)^2 is a square, where sopfr = A001414.

Terms

a(0) =1a(1) =8a(2) =15a(3) =35a(4) =112a(5) =143a(6) =323a(7) =899a(8) =1763a(9) =3599a(10) =5183a(11) =10403a(12) =11663a(13) =19043a(14) =22499a(15) =32399a(16) =36863a(17) =39203a(18) =51983a(19) =57599a(20) =72899a(21) =79523a(22) =97343a(23) =121103a(24) =176399a(25) =186623a(26) =213443a(27) =272483a(28) =324899a(29) =359999