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 A272242 #23 Sep 24 2018 08:49:24 %S A272242 9,81,625,729,87808,14641,130321,6561,65536,59049,78125 %N A272242 a(n) is the least number c such that there are exactly n abc-hits with third member c, or 0 if no such c exists. %C A272242 An abc-hit is a triple of coprime positive integers a, b, c such that a + b = c and rad(abc) < c, where rad(n) is the largest squarefree number dividing n. %C A272242 Conjecture: a(n) > 0 for all n. - _Jianing Song_, Sep 21 2018 %H A272242 Wikipedia, <a href="http://en.wikipedia.org/wiki/Abc_conjecture">abc conjecture</a> %e A272242 a(2) = 81 because there are exactly 2 abc-hits ((1, 80, 81) and (32, 49, 81)) with third member 81 and count of abc-hits with fixed third member c isn't equal to 2 for every c < 81. %Y A272242 Cf. A272243. %Y A272242 Cf. A120498, A130510 (possible values of c in abc-hits). %Y A272242 Cf. A225426 (triples of abc-hits). %Y A272242 Cf. A130512 (radicals of abc-hits). %Y A272242 Cf. A007947 (radicals). %K A272242 nonn,hard,more %O A272242 1,1 %A A272242 _Vladimir Letsko_, Apr 23 2016