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 A230870 #15 Jan 02 2017 20:03:28
%S A230870 4,11,3,3,4,7,16,4,45,5,8,27,4,7,4,11,495,16,3,3,11,8,47,4,5,49,16,16,
%T A230870 71,5,28,13,7,5,224,19,3,211,275,3,7,4,5,247,57,7,7,17,4,42,4,7,11,25,
%U A230870 4,49,3,4,7,7,25,27,37,4,5,16,3,4
%N A230870 Class numbers h-tilde_n^{+} corresponding to the primes listed in A230869.
%C A230870 Taken from the "Main Table" of Schoof.
%C A230870 There is a very slight chance that a(n) is only a proper divisor of the actual class number (see the Schoof and Miller articles for details).
%H A230870 John C. Miller, <a href="https://arxiv.org/abs/1405.1094">Class numbers of totally real fields and applications to the Weber class number problem</a>, arXiv:1405.1094 [math.NT], 2014.
%H A230870 John C. Miller, <a href="https://arxiv.org/abs/1407.2373">Real cyclotomic fields of prime conductor and their class numbers</a>, arXiv:1407.2373 [math.NT], 2014.
%H A230870 Rene Schoof, <a href="https://doi.org/10.1090/S0025-5718-02-01432-1">Class numbers of real cyclotomic fields of prime conductor</a>, Math. Comp., 72 (2002), 913-937.
%Y A230870 Cf. A230869.
%K A230870 nonn
%O A230870 1,1
%A A230870 _N. J. A. Sloane_, Nov 06 2013