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 A309300 #9 Jul 23 2019 08:39:40 %S A309300 0,0,0,0,1,3,10,27,70,178,438,1056,2496,5824,13440,30720,69632,156672, %T A309300 350208,778240,1720320,3784704,8290304,18087936,39321600,85196800, %U A309300 184025088,396361728,851443712,1824522240,3900702720,8321499136,17716740096,37648072704 %N A309300 (1/8) times the sum of the elements of all subsets of [n] whose sum is divisible by eight. %H A309300 Alois P. Heinz, <a href="/A309300/b309300.txt">Table of n, a(n) for n = 0..1000</a> %H A309300 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (6,-12,8). %F A309300 G.f.: -x^4*(16*x^9-8*x^8+4*x^7-6*x^6+2*x^5+4*x^4-5*x^3+4*x^2-3*x+1) / (2*x-1)^3. %Y A309300 Column k=8 of A309280. %K A309300 nonn,easy %O A309300 0,6 %A A309300 _Alois P. Heinz_, Jul 21 2019