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 A260998 #56 Feb 02 2020 21:36:21 %S A260998 1,2,3,3,3,4,4,4,4,4,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7, %T A260998 7,7,7,7,7,8,7,8,8,8,8,8,8,8,8,8,8,8,8,8,8,9,9,9,9,9,9,9,9,9,9,9,9,9, %U A260998 9,9,9,10,10,10,9,10,10,10,10,10,10,10,10,10,10,10,10,10,10,10 %N A260998 Maximal size of a subset of Z_n with distinct sums of pairs (of distinct elements). %H A260998 Fausto A. C. Cariboni, <a href="/A260998/b260998.txt">Table of n, a(n) for n = 1..254</a> %H A260998 Fausto A. C. Cariboni, <a href="/A260998/a260998_2.txt">S_2-sets that yield a(n) for n = 2..254</a>, Mar 24 2018. %H A260998 H. Haanpaa, A. Huima and Patric R. J. Östergård, <a href="/A004135/a004135.pdf">Sets in Z_n with Distinct Sums of Pairs</a>, in Optimal discrete structures and algorithms (ODSA 2000). Discrete Appl. Math. 138 (2004), no. 1-2, 99-106. [Annotated scanned copies of four pages only from preprint of paper] %H A260998 H. Haanpaa, A. Huima and Patric R. J. Östergård, <a href="https://doi.org/10.1016/S0166-218X(03)00273-7">Sets in Z_n with Distinct Sums of Pairs</a>, in Optimal discrete structures and algorithms (ODSA 2000). Discrete Appl. Math. 138 (2004), no. 1-2, 99-106. %F A260998 By the pigeonhole principle, C(a(n),2) <= n, yielding upper bound a(n) <= floor((1+sqrt(8*n+1))/2). - _Rob Pratt_, Nov 27 2017 %Y A260998 Cf. A004135, A004136, A260999. %K A260998 nonn %O A260998 1,2 %A A260998 _N. J. A. Sloane_, Aug 10 2015 %E A260998 a(1)-a(90) from H. Haanpaa, A. Huima and Patric R. J. Östergård (see link), Nov 08 2000 %E A260998 a(1)-a(90) confirmed by _Fausto A. C. Cariboni_, Nov 09 2017