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 A081642 #6 Dec 29 2019 17:59:37
%S A081642 10,13,18,19,22,27,28,31,37,40,45,46,54,55,58,63,67,72,73,76,82,85,90,
%T A081642 91,94,99,103,108,109,112,117,118,126,127,130,135,136,139,145,148,153,
%U A081642 154,157,162,163,166,171,172,175,180,181,184,189,190,193,198,199,202
%N A081642 Integers congruent to 0, 1 or 4 (mod 9) which are not squares.
%D A081642 Mark A. Herkommer, Number Theory, A Programmer's Guide, McGraw-Hill, New York, 1999, page 315.
%t A081642 Select[ Range[206], (Mod[ #, 9] == 0 || Mod[ #, 9] == 1 || Mod[ #, 9] == 4) && !IntegerQ[ Sqrt[ # ]] & ]
%t A081642 Select[Flatten[#+{0,1,4}&/@(9*Range[0,30])],!IntegerQ[Sqrt[#]]&] (* _Harvey P. Dale_, Dec 29 2019 *)
%Y A081642 Cf. A028837.
%K A081642 easy,nonn
%O A081642 1,1
%A A081642 _Robert G. Wilson v_, Mar 26 2003