This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A064128 #9 Jan 18 2019 13:56:37
%S A064128 2,2,2,2,2,2,2,2,4,4,4,4,4,4,4,4,16,2,4,4,2,2,16,2,4,8,4,4,2,2,4,8,4,
%T A064128 4,8,8,32,4,4,4,4,2,16,8,8,4,8,4,8,2,8,8,8,4,4,16,8,8,8,16,8,2,16,8,
%U A064128 16,8,4,4,4,32,2,8,16,8,8,4,4,16,8,8,4,8,128
%N A064128 Number of divisors of 6^n - 1 that are relatively prime to 6^m - 1 for all 0 < m < n.
%H A064128 Sam Wagstaff, Cunningham Project, <a href="https://homes.cerias.purdue.edu/~ssw/cun/">Factorizations of 6^n-1, n odd, n<330</a>
%t A064128 a = {1}; Do[ d = Divisors[ 6^n - 1 ]; l = Length[ d ]; c = 0; k = 1; While[ k < l + 1, If[ Union[ GCD[ a, d[ [ k ] ] ] ] == {1}, c++ ]; k++ ]; Print[ c ]; a = Union[ Flatten[ Append[ a, Transpose[ FactorInteger[ 6^n - 1 ] ][ [ 1 ] ] ] ] ], {n, 1, 66} ]
%o A064128 (PARI) a(n) = sumdiv(6^n-1, d, vecsum(vector(n-1, k, gcd(d, 6^k-1) == 1)) == n-1); \\ _Michel Marcus_, Jun 23 2018
%Y A064128 Cf. A063982.
%K A064128 nonn
%O A064128 1,1
%A A064128 _Robert G. Wilson v_, Sep 10 2001
%E A064128 a(67)-a(83) from _Jon E. Schoenfield_, Jun 23 2018