# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a160422 Showing 1-1 of 1 %I A160422 #9 Feb 24 2021 02:48:18 %S A160422 0,7,19,41,63,87,131,193,235,259,303,367,435,527,675,837,919,943,987, %T A160422 1051,1119,1211,1359,1523,1631,1723,1875,2071,2299,2631,3087,3489, %U A160422 3651,3675,3719,3783,3851,3943,4091,4255,4363,4455,4607,4803,5031,5363,5819,6223,6411 %N A160422 Number of "ON" cells at n-th stage in simple 2-dimensional cellular automaton whose virtual skeleton is a polyedge as the toothpick structure of A139250 but with toothpicks of length 6. %C A160422 a(n) is also the number of grid points that are covered after n-th stage by an polyedge as the toothpick structure of A139250, but with toothpicks of length 6. %H A160422 David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, 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 A160422 N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS %F A160422 a(n) = A147614(n)+4*A139250(n) = A160420(n)+2*A139250(n) since each toothpick covers exactly four more grid points than the corresponding toothpick in A147614. %Y A160422 Cf. A139250, A139251, A147614, A160118, A160120, A160170, A160420, A160430. %K A160422 nonn %O A160422 0,2 %A A160422 _Omar E. Pol_, May 20 2009 %E A160422 More terms and formula from _Nathaniel Johnston_, Nov 13 2010 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE