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 A212190 #15 Nov 23 2018 10:30:14 %S A212190 25,49,81,100,196,289,324,400,529,784,1089,1156,1296,1600,2116,3136, %T A212190 4225,4356,4624,5184,6400,8464,12544,16641,16900,17424,18496,20736, %U A212190 25600,33856,50176,66049,66564,67600,69696,73984,82944,102400,135424,200704,263169 %N A212190 Squares that are the sum of exactly three distinct powers of 2. %C A212190 Squares with exactly three ones in their binary representation: A000120(a(n)) = 3; %C A212190 squares in A014311; %C A212190 a(n) = A212191(n)^2. %H A212190 Giovanni Resta, <a href="/A212190/b212190.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Reinhard Zumkeller) %t A212190 Select[Range[1000]^2, DigitCount[#, 2, 1] == 3&] (* _Jean-François Alcover_, Nov 07 2016 *) %o A212190 (Haskell) %o A212190 a212190 n = a212190_list !! (n-1) %o A212190 a212190_list = filter ((== 1) . a010052) a014311_list %Y A212190 Cf. A010052, A212192. %K A212190 nonn %O A212190 1,1 %A A212190 _Reinhard Zumkeller_, May 03 2012