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 A269904 #10 Mar 12 2016 22:23:00 %S A269904 2,0,3117,504182416 %N A269904 Smallest magic sum for any n X n magic square filled with primes in an arithmetic progression, or 0 if no such magic square exists. %C A269904 a(n) > 0 for every n >= 3 under Dickson's conjecture. %D A269904 Joseph S. Madachy, "Magic and Antimagic Squares." Ch. 4 in Madachy's Mathematical Recreations, New York: Dover, 1979, p. 95. %D A269904 Clifford A. Pickover, The Mathematics of Oz: Mental Gymnastics from Beyond the Edge, Cambridge University Press, 2002, p. 327. %H A269904 Wikipedia, <a href="http://en.wikipedia.org/wiki/Magic_square">Magic square</a> %H A269904 Wikipedia, <a href="https://en.wikipedia.org/wiki/Primes_in_arithmetic_progression">Primes in arithmetic progression</a> %H A269904 <a href="/index/Mag#magic">Index entries for sequences related to magic squares</a> %e A269904 n = 3 %e A269904 |----|----|----| %e A269904 |1669| 199|1249| %e A269904 |----|----|----| %e A269904 | 619|1039|1459| %e A269904 |----|----|----| %e A269904 | 829|1879| 409| %e A269904 |----|----|----| %e A269904 . %e A269904 n = 4 %e A269904 |---------|---------|---------|---------| %e A269904 | 53297929|189093589|179393899| 82396999| %e A269904 |---------|---------|---------|---------| %e A269904 |159994519|101796379|111496069|130895449| %e A269904 |---------|---------|---------|---------| %e A269904 |121195759|140595139|150294829| 92096689| %e A269904 |---------|---------|---------|---------| %e A269904 |169694209| 72697309| 62997619|198793279| %e A269904 |---------|---------|---------|---------| %Y A269904 Cf. A269324, A269905. %K A269904 nonn,hard,more %O A269904 1,1 %A A269904 _Arkadiusz Wesolowski_, Mar 07 2016