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 A229942 #11 Nov 16 2013 14:19:43 %S A229942 0,1,2,2,2,2,2,3,3,2,3,4,3,2,3,4,3,3,4,4,3,2,4,6,4,2,3,4,4,4,4,5,4,2, %T A229942 4,6,4,2,4,6,5,4,4,4,3,2,5,8,5,3,4,4,4,4,5,6,4,2,5,8,5,2,4,6,5,4,4,4, %U A229942 4,4,6,9,6,2,3,4,4,4,6,8,5,2,5,8,5,2 %N A229942 Number of exposed toothpick endpoints in the n-th row of the toothpick structure of A229940 (also A229950). %C A229942 The second bisection gives A000005. %C A229942 For more information see A229940. %H A229942 Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poldiv13.jpg">Illustration of initial terms of the divisor function (A000005)</a>, see the third picture. %H A229942 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> %H A229942 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %e A229942 Illustration of initial terms: %e A229942 --------------------------------------------------- %e A229942 A229940 Diagram n a(n) A000005 %e A229942 --------------------------------------------------- %e A229942 . 1 0 %e A229942 . 2 1 1 %e A229942 1; | 3 2 %e A229942 0; 4 2 2 %e A229942 1; | 5 2 %e A229942 0; 6 2 2 %e A229942 1; | 7 2 %e A229942 0; 8 3 3 %e A229942 1, 1; | | 9 3 %e A229942 0, 1; | 10 2 2 %e A229942 1, 1; | | 11 3 %e A229942 0, 0; 12 4 4 %e A229942 1, 1; | | 13 3 %e A229942 0, 1; | 14 2 2 %e A229942 1, 1; | | 15 3 %e A229942 0, 0; 16 4 4 %e A229942 1, 1; | | 17 3 %e A229942 0, 1; | 18 3 3 %e A229942 1, 1, 1; | | | 19 4 %e A229942 0, 0, 1; | 20 4 4 %e A229942 1, 1, 1; | | | 21 3 %e A229942 0, 1, 1; | | 22 2 2 %e A229942 1, 1, 1; | | | 23 4 %e A229942 0, 0, 0; 24 6 6 %e A229942 1, 1, 1; | | | 25 4 %e A229942 0, 1, 1; | | 26 2 2 %e A229942 1, 1, 1; | | | 27 3 %e A229942 0, 0, 1; | 28 4 4 %e A229942 1, 1, 1; | | | 29 4 %e A229942 0, 1, 0; | 30 4 4 %e A229942 1, 1, 1; | | | 31 4 %e A229942 0, 0, 1; | 32 5 5 %e A229942 1, 1, 1, 1; | | | | %e A229942 --------------------------------------------------- %Y A229942 Cf. A000005, A139250, A139251, A229940, A229950, A229951. %K A229942 nonn %O A229942 1,3 %A A229942 _Omar E. Pol_, Oct 04 2013