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 A183127 #26 Aug 01 2023 07:54:34 %S A183127 0,1,6,16,16,40,16,40,40,112,16,40,40,112,40,112,112,328,16,40,40,112, %T A183127 40,112,112,328,40,112,112,328,112,328,328,976,16,40,40,112,40,112, %U A183127 112,328,40,112,112,328,112,328,328,976,40,112,112,328,112,328,328,976 %N A183127 Number of toothpicks added at n-th stage to the toothpick structure of A183126. %C A183127 Essentially the first differences of A183126. %H A183127 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 A183127 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 A183127 a(n) = 4*(1 + 3^A000120(n-2)), n >= 3. - _Nathaniel Johnston_, Apr 06 2011 %t A183127 a[n_] := 4*(1 + 3^DigitCount[n-2, 2, 1]); a[0] = 0; a[1] = 1; a[2] = 6; Array[a, 100, 0] (* _Amiram Eldar_, Aug 01 2023 *) %Y A183127 Cf. A000120, A139250, A139251, A160173, A161411, A183126, A183149. %K A183127 nonn %O A183127 0,3 %A A183127 _Omar E. Pol_, Mar 28 2011 %E A183127 a(0)-a(10) confirmed and a(11)-a(35) added by _John W. Layman_, Mar 30 2011 %E A183127 a(36)-a(47) from _Nathaniel Johnston_, Apr 06 2011 %E A183127 More terms from _Amiram Eldar_, Aug 01 2023