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 A145819 #7 Jun 02 2025 00:41:41 %S A145819 1,1,3,5,9,11,17,21,33,35,41,43,65,69,81,85,129,131,137,139,161,163, %T A145819 169,171,257,261,273,277,321,325,337,341 %N A145819 Union of A145812 and A145818 with double repetition of 1, so that a(1)=1, a(2)=1. %C A145819 Theorem. For every even integer m there exists a representation of the form m=a(r)+a(s). If A(x) is the counting function of a(n)<=x, then A(x)=O(sqrt(x))and Omega(sqrt(x)). Conjecture. The sequence is minimal in the following sense: if any sequence has the counting function B(x)<=A(x) for all x>=1 and B(x) < A(x) for x>=x_0, then there exists an even integer N which is not expressible as a sum of two terms of such sequence. %Y A145819 Cf. A145812, A145818. %K A145819 nonn %O A145819 1,3 %A A145819 _Vladimir Shevelev_, Oct 20 2008