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 A161182 #9 Feb 21 2019 23:23:29
%S A161182 1,1,3,5,6,9,9,12,13,16,16,19,20,22,25,25,26,30,31,33,34,36,38,41,40,
%T A161182 43,46,47,48,51,53,53,56,57,60,61,64,66,65,68,69,72,76,75,78,78,83,82,
%U A161182 82,89,90,88,89,95,96,100,101,98,104,103,105,110,108,112,115,115,118,120
%N A161182 Successive differences between positions of squares in list of nonprimes.
%H A161182 Harvey P. Dale, <a href="/A161182/b161182.txt">Table of n, a(n) for n = 1..1000</a>
%F A161182 a(n) = A078435(n) - A078435(n-1). - _R. J. Mathar_, Jun 22 2009
%p A161182 A038107 := proc(n) numtheory[pi]( n^2) ; end: A078435 := proc(n) n^2-A038107(n) ; end: A161182 := proc(n) A078435(n)-A078435(n-1) ; end: seq(A161182(n),n=1..100) ; # _R. J. Mathar_, Jun 22 2009
%t A161182 With[{nn=5000},Differences[Flatten[Position[Complement[Range[0,nn], Prime[ Range[ PrimePi[nn]]]],_?(IntegerQ[Sqrt[#]]&)]]]] (* _Harvey P. Dale_, Mar 03 2014 *)
%Y A161182 Cf. A078435, sequence of positions of squares in sequence of nonprimes.
%K A161182 nonn
%O A161182 1,3
%A A161182 _Daniel Tisdale_, Jun 05 2009
%E A161182 Corrected and extended by _R. J. Mathar_, Jun 22 2009