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 A246809 #15 Nov 28 2014 23:39:15 %S A246809 12801,136497879001,422240040001,18677955240001 %N A246809 Composite numbers such that n^(b^n) == (-1)^b (mod C_b(n)), where C_b(n) = n*b^n+1 (A210339). %H A246809 J. M. Grau and A. M. Oller-Marcen, <a href="http://dx.doi.org/10.1090/S0025-5718-2011-02489-0">An O(log^2(N)) time primality test for generalized Cullen numbers</a>, Math. Comp., Vol. 80, Num. 276 (2011), 2315-2323. %Y A246809 Cf. A210339. %K A246809 nonn,hard,more %O A246809 1,1 %A A246809 _Felix Fröhlich_, Nov 16 2014