Numbers k such that k^2 divides 5^k + 1.

Terms

a(0) =1a(1) =3a(2) =21a(3) =609a(4) =903a(5) =2667a(6) =9429a(7) =26187a(8) =77343a(9) =114681a(10) =159663a(11) =212541a(12) =273441a(13) =405447a(14) =1197483a(15) =1357503a(16) =1398747a(17) =3325749a(18) =4451181a(19) =4630227a(20) =6099429a(21) =6865509a(22) =8620941a(23) =9139263a(24) =11757963a(25) =13047447a(26) =20277201a(27) =26992707a(28) =34727007a(29) =37088709