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 A188916 #13 Apr 13 2025 03:15:18 %S A188916 0,1,3,5,6,7,9,10,11,12,13,14,16,17,18,19,20,21,22,23,24,25,26,28,29, %T A188916 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,52,53, %U A188916 54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,98,99,100 %N A188916 Where squares occur in the union of squares and powers of 2. %H A188916 Reinhard Zumkeller, <a href="/A188916/b188916.txt">Table of n, a(n) for n = 0..10000</a> %F A188916 A188915(a(n)) = A000290(n); A188915(A188917(n)) = A000079(n). %t A188916 seq[lim_] := -1 + Position[Union[2^Range[1, Floor[Log2[lim]], 2], Range[0, Floor[Sqrt[lim]]]^2], _?(IntegerQ[Sqrt[#]] &)] // Flatten; seq[10000] (* _Amiram Eldar_, Apr 13 2025 *) %o A188916 (Haskell) %o A188916 a188916 n = a188916_list !! n %o A188916 a188916_list = filter ((== 1) . a010052. a188915) [0..] %o A188916 -- _Reinhard Zumkeller_, May 19 2015 %Y A188916 Cf. A000079, A000290. %Y A188916 Cf. A188915, A188917, A010052, A006127 (subsequence). %K A188916 nonn %O A188916 0,3 %A A188916 _Reinhard Zumkeller_, Apr 14 2011