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 A047873 #12 Jul 06 2024 11:54:31 %S A047873 1,3,8,15,27,43,65,94,130,175,229,294,369,456,557,671,800,944,1105, %T A047873 1283,1479,1695,1930,2187,2465,2765,3090,3439,3813,4213,4641,5096, %U A047873 5580,6095,6639,7216,7825,8466,9143,9855 %N A047873 a(n) = max_{r=1..n-1} ceiling(t(t(n)-t(r-1))/(n-r+1)), where t() = triangular numbers A000217. %C A047873 Another lower bound for Honaker triangle problem (A047837); conjectured to be exact value. %F A047873 Empirical g.f.: -x*(x^15 - 3*x^14 + 3*x^13 - 5*x^12 + 5*x^11 - 9*x^10 + 7*x^9 - 10*x^8 + 7*x^7 - 9*x^6 + 5*x^5 - 6*x^4 + 2*x^3 - 3*x^2 - 1) / ((x-1)^4*(x^2-x+1)*(x^2+1)*(x^2+x+1)^2*(x^4-x^2+1)). [_Colin Barker_, Jan 18 2013] %Y A047873 Cf. A047837, A047866. %K A047873 easy,nonn %O A047873 1,2 %A A047873 _Mike Keith_