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 A138326 #10 Oct 09 2021 04:42:37
%S A138326 1,2,4,6,9,11,14,16,25,26,35,36,41,45,49,51,64,81,100,121,144,169,196,
%T A138326 225,256,289,324,361,400,441,484,529,576,625,676,729,784,841,900,961,
%U A138326 1024,1089,1156,1225,1296,1369,1444,1521,1600,1681,1764,1849,1936,2025
%N A138326 Numbers not representable as p+g, where p is a prime and g is a primitive root of p.
%C A138326 This sequence appears to contain all the positive squares (A000290) and a few other numbers (A138327).
%H A138326 Amiram Eldar, <a href="/A138326/b138326.txt">Table of n, a(n) for n = 1..375</a>
%t A138326 seq[m_] := Module[{p = Select[Range[m], PrimeQ]}, Complement[Range[m], p + PrimitiveRootList[p] // Flatten]]; seq[2000] (* _Amiram Eldar_, Oct 09 2021 *)
%Y A138326 Cf. A000290, A060749 (primitive roots), A138327.
%K A138326 nonn
%O A138326 1,2
%A A138326 _T. D. Noe_, Mar 14 2008