A261695 - OEIS

%I #21 May 17 2024 15:24:06

%S 0,4,12,12,36,12,36,60,84,12,36,60,84,108,132,156,180,12,36,60,84,108,

%T 132,156,180,204,228,252,276,300,324,348,372,12,36,60,84,108,132,156,

%U 180,204,228,252,276,300,324,348,372,396,420,444,468,492,516,540,564,588,612,636,660,684,708,732,756,12,36,60,84,108

%N First differences of A256534.

%C Number of cells turned ON at n-th stage of cellular automaton of A256534.

%C Similar to A256531 which shares infinitely many terms.

%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 It appears that a(n) = 4 * A241717(n-1), n >= 1.

%e With the positive terms written as an irregular triangle in which the row lengths are the terms of A011782 the sequence begins:

%e 4;

%e 12;

%e 12, 36;

%e 12, 36, 60, 84;

%e 12, 36, 60, 84, 108, 132, 156, 180;

%e 12, 36, 60, 84, 108, 132, 156, 180, 204, 228, 252, 276, 300, 324, 348, 372;

%e ...

%o (GW-BASIC)

%o 10 'a261695 First 2^z-1 terms:

%o 20 z=6: defdbl a: for i=1 to z: for j=0 to 2^(i-1)-1: n=n+1: a(n)=4^i + 3*(2*j)^2: print a(n)-a(n-1); : next j: next i: end

%Y Cf. A011782, A139251, A147582, A161411, A161415, A241717, A256531, A256534.

%K nonn,tabf

%O 0,2

%A _Omar E. Pol_, Sep 24 2015