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 A081646 #4 Sep 10 2024 11:44:33
%S A081646 50,53,58,65,74,85,98,99,102,107,114,123,134,147,148,151,156,163,172,
%T A081646 183,197,200,205,212,221,232,245,246,249,254,261,270,281,294,295,298,
%U A081646 303,310,319,330,343,344,347,352,359,368,379,392,393,396,401,408,417
%N A081646 Integers congruent to 0, 1, 4, 9, 16, 25 or 36 (mod 49) which are not squares.
%D A081646 Mark A. Herkommer, Number Theory, A Programmer's Guide, McGraw-Hill, New York, 1999, page 315.
%t A081646 Select[ Range[427], (Mod[ #, 49] == 0 || Mod[ #, 49] == 1 || Mod[ #, 49] == 4 || Mod[ #, 49] == 9 || Mod[ #, 49] == 16 || Mod[ #, 49] == 25 || Mod[ #, 49] == 36) && !IntegerQ[ Sqrt[ # ]] & ]
%t A081646 Select[Range[500],MemberQ[{0,1,4,9,16,25,36},Mod[#,49]]&&!IntegerQ[Sqrt[#]]&] (* _Harvey P. Dale_, Sep 10 2024 *)
%K A081646 easy,nonn
%O A081646 1,1
%A A081646 _Robert G. Wilson v_, Mar 26 2003