Numbers k such that k^2 divides 13^k + 1.

Terms

a(0) =1a(1) =7a(2) =203a(3) =11977a(4) =154553a(5) =353423a(6) =4482037a(7) =9904979a(8) =20851957a(9) =69262991a(10) =264440183a(11) =6824905927a(12) =7803226417a(13) =17244568439a(14) =47773414171a(15) =57280493557a(16) =120586867331a(17) =197922271883a(18) =218692031341a(19) =249815987281a(20) =409580786629a(21) =460390358603a(22) =802768833013a(23) =963574941161