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 A172083 #19 Jan 03 2022 21:09:58 %S A172083 1,-3,2,-1,-1,1,1,-1,-1,1,5,-5,-691,691,7,-7,-3617,3617,43867,-43867, %T A172083 -174611,174611,854513,-854513,-236364091,236364091,8553103,-8553103, %U A172083 -23749461029,23749461029,8615841276005,-8615841276005,-7709321041217,7709321041217,2577687858367 %N A172083 1, followed by numerators of first differences of Bernoulli numbers (B(i) - B(i-1)). %e A172083 Bernoulli numbers: 1, -1/2, 1/6, 0, -1/30, 0, 1/42, 0, -1/30, 0, 5/66, ... %e A172083 First differences: -3/2, 2/3, -1/6, -1/30, 1/30, 1/42, -1/42, -1/30, ... %e A172083 Numerators: -3, 2, -1, -1, 1, 1, -1, -1, 1, 5, -5, -691, 691, 7, ... %e A172083 Denominators: 2, 3, 6, 30, 30, 42, 42, 30, 30, 66, 66, 2730, ... %Y A172083 Cf. A027641/A027642. %Y A172083 For denominators see A051717. %K A172083 sign %O A172083 0,2 %A A172083 _Paul Curtz_, Jan 25 2010 %E A172083 Edited and more terms from _N. J. A. Sloane_, Apr 22 2021