1+6+6²+6³...6¹⁰⁰+6¹⁰¹ =
=(1+6)+6(1+6)+6²(1+6)...6¹⁰⁰(1+6)=
=7(1+6+6²......6¹⁰⁰) deci divizibil cu 7
(1+6+6²......6¹⁰⁰) =
=(1+6²)+6(1+6²).....6⁹⁸(1+6²) =
=37(1+6+.....6⁹⁸) deci divizibil cu 37
1+6+6²+6³....+6⁹⁷+6⁹⁸+6¹⁰⁰=
(1+6+6² )+......6⁹⁷(1+6+6²)=43(1+....6⁹⁷) deci divizibil cu 43