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A151922 Number of first-quadrant cells (including the two boundaries) that are "ON" after n-th stage of the Holladay-Ulam cellular automaton. 5

%I #29 Jul 15 2023 06:20:41

%S 1,3,5,9,11,15,19,29,31,35,39,49,53,63,73,101,103,107,111,121,125,135,

%T 145,173,177,187,197,225,235,263,291,373,375,379,383,393,397,407,417,

%U 445,449,459,469,497,507,535,563,645

%N Number of first-quadrant cells (including the two boundaries) that are "ON" after n-th stage of the Holladay-Ulam cellular automaton.

%C See A079314, the first differences and A147562, the main entry for this CA, for further information.

%H Paolo Xausa, <a href="/A151922/b151922.txt">Table of n, a(n) for n = 0..10000</a>

%H 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 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 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>

%F a(n) = A079316(2n).

%t A151922list[nmax_]:=Accumulate[Join[{1},3^(DigitCount[Range[nmax],2,1]-1)+1]];A151922list[100] (* _Paolo Xausa_, Jun 29 2023 *)

%Y Cf. A079314, A079316, A139250, A147562, A160406.

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_, Aug 05 2009

%E Extended (a(30)-a(47)) and edited by _Omar E. Pol_, Nov 21 2010

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Last modified April 18 15:16 EDT 2024. Contains 371780 sequences. (Running on oeis4.)