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 A051713 #13 May 03 2015 11:00:07 %S A051713 1,60,60,70,84,504,120,990,165,572,1092,2730,280,4080,2448,1938,855, %T A051713 7980,1540,10626,3036,4600,7800,17550,819,21924,12180,8990,7440,32736, %U A051713 5984,39270,5355,15540,25308,54834,4940,63960,34440 %N A051713 Denominator of b(n)-b(n+1), where b(n) = n/((n+1)(n+2)) = A026741/A045896. %H A051713 M. Kaneko, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL3/KANEKO/AT-kaneko.html">The Akiyama-Tanigawa algorithm for Bernoulli numbers</a>, J. Integer Sequences, 3 (2000), #00.2.9. %e A051713 0, 1/60, 1/60, 1/70, 1/84, 5/504, 1/120, 7/990, 1/165, 3/572,... %t A051713 Denominator[#[[1]]-#[[2]]&/@(Partition[#[[1]]/(#[[2]]#[[3]])&/@Partition[ Range[50],3,1],2,1])] (* _Harvey P. Dale_, Nov 15 2014 *) %Y A051713 Cf. A051712. Row 3 of table in A051714/A051715. %K A051713 nonn,frac,easy %O A051713 1,2 %A A051713 _N. J. A. Sloane_