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 A269298 #28 Aug 02 2024 04:31:37 %S A269298 1,2,2,4,6,8,16,28,50,100,196,388,786,1600,3280,6780,14060,29280, %T A269298 61232,128414,270084,569514,1203564,2548770,5407754,11493312,24465960, %U A269298 52157508,111342192,237985596,509275390,1091017632,2339687834,5022312654,10790564790 %N A269298 Central nonzero values of A231599. %C A269298 Rows of A231599 whose row number is divisible by four have positive central values. a(n) is the central value of row 4n. They are also the maximal value of that row, so a(n) = A086376(4n). %C A269298 a(1) = a(2) = 2. Apart from that the sequence is strictly increasing. %H A269298 Alois P. Heinz, <a href="/A269298/b269298.txt">Table of n, a(n) for n = 0..250</a> (first 101 trms from Tilman Piesk) %H A269298 Dorin Andrica and Ovidiu Bagdasar, <a href="https://doi.org/10.37193/CJM.2019.01.01">On some results concerning the polygonal polynomials</a>, Carpathian Journal of Mathematics (2019) Vol. 35, No. 1, 1-11. %H A269298 Tilman Piesk, <a href="http://paste.watchduck.net/1602/A231599_centered.html">A231599 as a centered table</a> (first 11 values visible) %F A269298 a(n) = A231599( 4n, A000217(4n)/2 ) = A086376(4n). %e A269298 For n = 5, A231599( 4n, A000217(4n)/2 ) = A231599(20, 105) = 8, so a(5)=8. %e A269298 For n = 5, A086376(4n) = A086376(20) = 8, so a(5)=8. %Y A269298 Cf. A231599, A086376. %K A269298 nonn %O A269298 0,2 %A A269298 _Tilman Piesk_, Feb 21 2016