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 A213446 N1674 #27 Jun 29 2019 06:30:12
%S A213446 1,5,251,19087,1070017,134211265,703604254357,8164168737599,
%T A213446 8092989203533249,12600467236042756559,8136836498467582599787,
%U A213446 440495080723071436695083,11816334311483623162503196771,19935908483981827227406276943,239295997830894998532654988331179
%N A213446 Numerators of higher order Bernoulli numbers.
%C A213446 See Nørlund for precise definition.
%C A213446 See A002657 which is the main entry for this sequence. - _Peter Luschny_, Oct 02 2016
%D A213446 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%H A213446 N. E. Nørlund, <a href="https://eudml.org/doc/204170">Vorlesungen über Differenzenrechnung</a>, Springer, 1924, p. 461.
%p A213446 # Function B(n,x) defined in A213449.
%p A213446 A213446 := n -> numer(B(2*n,2*n)):
%p A213446 seq(A213446(n), n=0..14); # _Peter Luschny_, Oct 02 2016
%t A213446 a[n_] := Numerator[NorlundB[2n, 2n]];
%t A213446 Table[a[n], {n, 0, 14}] (* _Jean-François Alcover_, Jun 29 2019 *)
%Y A213446 Bisection (even indices) of A002657.
%K A213446 nonn,frac
%O A213446 0,2
%A A213446 _N. J. A. Sloane_, Jun 12 2012
%E A213446 More terms at the suggestion of _Altug Alkan_ from _Peter Luschny_, Oct 02 2016