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 A274050 #13 Sep 04 2017 09:01:38 %S A274050 1,23,71,79,95,135,142,143,167,190,191,211,215,239,255,284,286,287, %T A274050 303,311,323,331,343,359,380,382,383,415,419,430,431,439,455,471,475, %U A274050 499,503,519,527,568,572,574,575,583,591,599,622,623,646,647,671,683,695 %N A274050 Numbers that cannot be expressed as the sum of two nonzero squares and at most one power of two. %C A274050 The number 1 is considered a power of two. %H A274050 Chai Wah Wu, <a href="/A274050/b274050.txt">Table of n, a(n) for n = 1..10000</a> %H A274050 Dave Platt, Tim Trudgian, <a href="https://arxiv.org/abs/1610.01672">On the sum of two squares and at most two powers of 2</a>, arXiv:1610.01672 [math.NT], 2016. %t A274050 nR[n_] := (SquaresR[2, n] + Plus @@ Pick[{-4, 4}, IntegerQ /@ Sqrt[{n, n/2}]])/8; bad[n_] := nR[n] == 0 && Block[{k = 1}, While[k < n && nR[n - k] == 0, k *= 2]; k >= n]; Select[Range@ 1000, bad] %Y A274050 Cf. A000404, A273812. %K A274050 nonn %O A274050 1,2 %A A274050 _Giovanni Resta_, Jun 08 2016