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 A033629 #30 Jul 06 2025 11:24:43
%S A033629 23,25,33,35,43,45,67,92,94,96,111,121,136,143,160,165,170,172,187,
%T A033629 194,204,226,231,248,265,270,280,287,292,297,302,304,314,331,336,346,
%U A033629 348,353,368,380,397,407,419,424,446,463,468,473,475,480,490,495,507
%N A033629 Numbers that are not the sum of two distinct Ulam numbers.
%D A033629 R. K. Guy, Unsolved Problems in Number Theory, C4
%H A033629 Ruud H.G. van Tol, <a href="/A033629/b033629.txt">Table of n, a(n) for n = 1..11944</a> (upto 2^16)
%H A033629 Shyam Sunder Gupta, <a href="https://doi.org/10.1007/978-981-97-2465-9_18">Ulam Numbers</a>. In: Exploring the Beauty of Fascinating Numbers. Springer Praxis Books(). Springer, Singapore, (2025).
%H A033629 Ivano Salvo and Agnese Pacifico, <a href="https://arxiv.org/abs/1807.11792">Computing Integer Sequences: Filtering vs Generation (Functional Pearl)</a>, arXiv:1807.11792 [cs.PL], 2018.
%t A033629 terms = 1000; ulams = {1, 2};
%t A033629 Do[AppendTo[ulams, n = Last[ulams]; While[n++; Length[ DeleteCases[ Intersection[ ulams, n - ulams], n/2, 1, 1]] != 2]; n], {terms}];
%t A033629 uu = Total /@ Subsets[ulams, {2}] // Union;
%t A033629 Complement[Range[Last[uu]], uu] // Take[#, {3, terms+2}]& (* _Jean-François Alcover_, Dec 02 2018 *)
%o A033629 (PARI) aupto(N)= my(S=Vec([1, 1], N), U=[]); for(i=1, N, if(1==S[i], for(j=1, #U, my(t=i+U[j]); if(t>N, break); S[t]++); U=concat(U, i))); Vec(select(x->!x, S, 1)) \\ _Ruud H.G. van Tol_, Jul 05 2025
%Y A033629 Cf. A002858.
%K A033629 nonn
%O A033629 1,1
%A A033629 _Jud McCranie_