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 A159786 #14 Feb 24 2021 02:48:18 %S A159786 0,0,0,4,8,8,12,32,48,48,52,64,72,76,104,176,224,224,228,240,248,252, %T A159786 280,336,368,372,392,424,444,480,608,864,960,960,964,976,984,988,1016, %U A159786 1072,1104,1108,1128,1160,1180,1216,1344,1536,1632,1636,1656 %N A159786 Total area of all squares and rectangles after n-th stage in the toothpick structure of A139250, assuming the toothpicks have length 2. %C A159786 Note that if n > 1 is a power of 2 then a(n) = n^2 - 2n. %H A159786 David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.] %H A159786 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 A159786 a(2^k) = A211012(k). - _Omar E. Pol_, Sep 25 2012 %Y A159786 Cf. A139250, A139251, A159787, A159788, A159789, A159796. %K A159786 nonn %O A159786 0,4 %A A159786 _Omar E. Pol_, Apr 28 2009 %E A159786 More terms from _Omar E. Pol_, Sep 25 2012