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 A211017 #19 Dec 24 2022 22:24:52 %S A211017 0,0,8,8,24,16,40,104,48,32,168,424,208,96,64,680,1704,848,416,192, %T A211017 128,2728,6824,3408,1696,832,384,256,10920,27304,13648,6816,3392,1664, %U A211017 768,512,43688,109924,54608,27296,13632,6784,3328,1536,1024 %N A211017 T(n,k) = total area of all squares and rectangles of area 2^(k-1) after 2^n stages in the toothpick structure of A139250, n>=1, k>=1, assuming the toothpicks have length 2. Triangle read by rows. %C A211017 All internal regions in the toothpick structure are squares and rectangles. The area of every internal region is a power of 2. %H A211017 N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a> %F A211017 T(n,k) = A211016(n,k)*2^(k-1). %F A211017 T(n,1) = 4*A020988(n-2), n>=2. %e A211017 For n = 5 in the toothpick structure after 2^5 stages we have that: %e A211017 T(5,1) = 168 is the total area of all squares of size 1 X 1. %e A211017 T(5,2) = 424 is the total area of all rectangles of size 1 X 2. %e A211017 T(5,3) = 208 is the total area of all squares of size 2 X 2 and of all rectangles of size 1 X 4. %e A211017 T(5,4) = 96 is the total area of all rectangles of size 2 X 4. %e A211017 T(5,5) = 64 is the total area of all rectangles of size 2 X 8. %e A211017 Triangle begins: %e A211017 0; %e A211017 0, 8; %e A211017 8, 24, 16; %e A211017 40, 104, 48, 32; %e A211017 168, 424, 208, 96, 64; %e A211017 680, 1704, 848, 416, 192, 128; %e A211017 2728, 6824, 3408, 1696, 832, 384, 256; %e A211017 10920, 27304, 13648, 6816, 3392, 1664, 768, 512; %Y A211017 Row sums give A211012. %Y A211017 Cf. A020988, A139250, A160124, A211016, A211018, A211019. %K A211017 nonn,tabl %O A211017 1,3 %A A211017 _Omar E. Pol_, Sep 21 2012