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 A003457 #20 Jun 22 2017 05:37:34
%S A003457 0,1,0,1,0,1,0,1,-1,14,-140,1804,-27413,487469,-10026347,236192434,
%T A003457 -6317862397,190439655627,-6425425249652,241207241774251,
%U A003457 -10020155328258126,458387180159766539,-22989944171828251745,1259023596072554784855,-75008667460769643668557
%N A003457 a(n) = ceiling(Bernoulli(2n)/(-4n)).
%D A003457 F. Hirzebruch et al., Manifolds and Modular Forms, Vieweg, 2nd ed. 1994, p. 130.
%D A003457 Douglas C. Ravenel, Complex cobordism theory for number theorists, Lecture Notes in Mathematics, 1326, Springer-Verlag, Berlin-New York, 1988, pp. 123-133.
%H A003457 T. D. Noe, <a href="/A003457/b003457.txt">Table of n, a(n) for n = 1..100</a>
%H A003457 R. C. Read, <a href="/A001004/a001004.pdf">On general dissections of a polygon</a>, Preprint (1974)
%H A003457 <a href="/index/Be#Bernoulli">Index entries for sequences related to Bernoulli numbers.</a>
%t A003457 Table[Ceiling[BernoulliB[2n]/(-4n)], {n, 24}] (* _Alonso del Arte_, Jul 11 2012 *)
%Y A003457 Cf. A003414 (floor instead of ceiling).
%K A003457 sign
%O A003457 1,10
%A A003457 _N. J. A. Sloane_