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 A102272 #8 Oct 13 2017 05:48:45
%S A102272 16,8,8,8,16,16,8,32,16,16,16,8,16,8,64,8,8,8,8,128,16,8,8,32
%N A102272 2-class number of Q(sqrt(-21p)) as p runs through primes in A102271.
%H A102272 H. Cohn and J. C. Lagarias, <a href="http://doi.org/10.1090/S0025-5718-1983-0717716-8">On the existence of fields governing the 2-invariants of the classgroup of Q(sqrt{dp}) as p varies</a>, Math. Comp. 41 (1983), 711-730.
%Y A102272 Cf. A102269, A102270, A102271, A102273, A102274, A102275.
%K A102272 nonn,more
%O A102272 1,1
%A A102272 _N. J. A. Sloane_, Feb 19 2005