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 A225388 #6 May 06 2013 01:04:03 %S A225388 25,125,169,243,256,289,625,841,1369,1681,2809,3125,3721,5329,9409, %T A225388 11881,12769,18769,22201,28561,37249,38809,54289,76729,83521,100489, %U A225388 113569,151321,160801,196249,201601,208849,292681,323761,375769,390625,410881,426409,452929,502681 %N A225388 Prime powers (A025475) representable as (p+q)/2, where p and q are distinct prime powers. %e A225388 a(1) = 25 = (1 + 49) / 2. %e A225388 a(2) = 125 = (81 + 169) / 2. %e A225388 a(3) = 169 = (49 + 289) / 2. %e A225388 a(4) = 243 = (125 + 361) / 2. %e A225388 a(5) = 256 = (169 + 343) / 2. %e A225388 a(6) = 289 = (49 + 529) / 2. %Y A225388 Cf. A025475, A225389. %K A225388 nonn %O A225388 1,1 %A A225388 _Alex Ratushnyak_, May 05 2013