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 A051218 #12 May 14 2017 03:00:44
%S A051218 0,1,3,6,7,13,19,24,33,40,45,48,49,54,87,97,118,147,166,174,192,199,
%T A051218 222,243,262,279,285,294,307,318,327,334,339,342,343,376,423,465,552,
%U A051218 637,678,685,720,801,880,894,931,957,1032,1105,1176,1182,1245,1312
%N A051218 Numbers of the form 7^x-y^2 >= 0.
%t A051218 max = 2000; Clear[f]; f[m_] := f[m] = Select[Table[7^x - y^2, {x, 0, m}, {y, 0, Ceiling[7^(x/2)]}] // Flatten // Union, 0 <= # <= max &]; f[1]; f[m = 2]; While[f[m] != f[m - 1], m++]; Print["m = ", m]; A051218 = f[m] (* _Jean-François Alcover_, May 14 2017 *)
%Y A051218 Cf. A201123.
%K A051218 nonn
%O A051218 1,3
%A A051218 _David W. Wilson_