Numbers k such that k^3 divides 10^(k^2) - 1.

Terms

a(0) =1a(1) =3a(2) =9a(3) =111a(4) =333a(5) =1467a(6) =6813a(7) =54279a(8) =84573a(9) =252081a(10) =607947a(11) =665667a(12) =1001001a(13) =1110519a(14) =1823841a(15) =3003003a(16) =3129201a(17) =12914001a(18) =13785399a(19) =22161609a(20) =22957083a(21) =37037037a(22) =41089203a(23) =49235049a(24) =64021761a(25) =92840751a(26) =108503721a(27) =111111111