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 A076285 #9 May 02 2018 22:35:12
%S A076285 1,7,37,43,217,259,1297,1333,1555,7777,9331,46657,46873,47989,55987,
%T A076285 279937,335923,1679617,1680913,1727605,2015539,10077697,10124569,
%U A076285 12093235,60466177,60473953,62193781,72559411,362797057,435356467,2176782337,2176828993,2178463249
%N A076285 Numbers of the form (6^{mr}-1)/(6^r-1) for positive integers m, r.
%H A076285 Robert Israel, <a href="/A076285/b076285.txt">Table of n, a(n) for n = 1..9380</a>
%H A076285 T. Chinburg and M. Henriksen, <a href="http://matwbn.icm.edu.pl/ksiazki/aa/aa29/aa2932.pdf">Sums of k-th powers in the ring of polynomials with integer coefficients</a>, Acta Arithmetica, 29 (1976), 227-250.
%p A076285 1, seq(seq((6^(m+r)-1)/(6^r-1), r = sort(convert(numtheory:-divisors(m),list),`>`)),m=0..15); # _Robert Israel_, May 02 2018
%K A076285 nonn
%O A076285 1,2
%A A076285 _N. J. A. Sloane_, Nov 06 2002