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 A002443 M0906 N0341 #37 Jan 08 2016 21:01:05
%S A002443 1,1,1,2,3,10,1382,420,10851,438670,7333662,51270780,7090922730,
%T A002443 2155381956,94997844116,68926730208040,1780853160521127,
%U A002443 541314450257070,52630543106106954746,15997766769574912140,10965474176850863126142,1003264444985926729776060,35069919669919290536128980
%N A002443 Numerator in Feinler's formula for unsigned Bernoulli number |B_{2n}|.
%C A002443 A002443/A002444 = |B_{2n}| (see also A000367/A002445).
%C A002443 a(n) is a nontrivial multiple of A000367(n) if gcd(a(n),A002444(n)) > 1. Furthermore, all terms here are positive, whereas the terms of A000367 retain the sign of B_{2n}, e.g., a(8)/A002444(8) = 10851/1530 is the absolute value of A000367(8)/A002445(8) = -3617/510 = B_{16}. - _M. F. Hasler_, Jan 05 2016
%D A002443 H. T. Davis, Tables of the Mathematical Functions. Vols. 1 and 2, 2nd ed., 1963, Vol. 3 (with V. J. Fisher), 1962; Principia Press of Trinity Univ., San Antonio, TX, Vol. 2, p. 208.
%D A002443 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002443 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002443 H. T. Davis, <a href="/A002443/a002443.pdf">Tables of the Mathematical Functions</a>, Vols. 1 and 2, 2nd ed., 1963, Vol. 3 (with V. J. Fisher), 1962; Principia Press of Trinity Univ., San Antonio, TX. [Annotated scan of pages 204-208 of Volume 2.]
%H A002443 <a href="/index/Be#Bernoulli">Index entries for sequences related to Bernoulli numbers.</a>
%F A002443 See Davis, Vol. 2, p. 206, second displayed equation, where a(n) appears as c_{2k}. Note that the recurrence for c_{2k} involves an extra term c_1 = 1 (which is not a term of the present sequence), and also the numbers M_i^{2k} given in A266743. However, given that contemporary Computer Algebra Systems can easily calculate Bernoulli numbers, and A002444 has a simple formula, the best way to compute a(n) today is via a(n) = A002444(n)*|B_{2n}|. - _N. J. A. Sloane_, Jan 08 2016
%Y A002443 Cf. A002444, A000367, A002445, A266742, A266743, A266911.
%K A002443 nonn,frac
%O A002443 0,4
%A A002443 _N. J. A. Sloane_
%E A002443 Name amended following a suggestion from _T. D. Noe_. - _M. F. Hasler_, Jan 05 2016
%E A002443 Edited with new definition, further terms, and scan of source by _N. J. A. Sloane_, Jan 08 2016