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 A081644 #5 Apr 08 2020 15:37:53 %S A081644 26,29,34,41,50,51,54,59,66,75,76,79,84,91,101,104,109,116,125,126, %T A081644 129,134,141,150,151,154,159,166,175,176,179,184,191,200,201,204,209, %U A081644 216,226,229,234,241,250,251,254,259,266,275,276,279,284,291,300,301,304 %N A081644 Integers congruent to 0, 1, 4, 9 or 16 (mod 25) which are not squares. %D A081644 Mark A. Herkommer, Number Theory, A Programmer's Guide, McGraw-Hill, New York, 1999, page 315. %H A081644 Robert Israel, <a href="/A081644/b081644.txt">Table of n, a(n) for n = 1..10000</a> %p A081644 remove(issqr, [seq(seq(25*i+j,j=[0,1,4,9,16]),i=1..50)]); # _Robert Israel_, Apr 08 2020 %t A081644 Select[ Range[308], (Mod[ #, 25] == 0 || Mod[ #, 25] == 1 || Mod[ #, 25] == 4 || Mod[ #, 25] == 9 || Mod[ #, 25] == 16) && !IntegerQ[ Sqrt[ # ]] & ] %K A081644 easy,nonn %O A081644 1,1 %A A081644 _Robert G. Wilson v_, Mar 26 2003