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 A194271 Number of toothpicks or D-toothpicks added at n-th stage to the structure of A194270. 19

%I

%S 0,1,4,8,16,22,24,22,40,40,32,32,56,74,96,50,88,72,32,48,72,104,128,

%T 112,144,144,152,96,152,178,240,122,184,136,32,48,72,108,144,144,184,

%U 188,200,176,272,274,416,250,288,272,216,144,208,292,384,332,376

%N Number of toothpicks or D-toothpicks added at n-th stage to the structure of A194270.

%C Essentially the first differences of A194270.

%H David Applegate, <a href="/A139250/a139250.anim.html">The movie version</a>

%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/To#toothpick">Index entries for sequences related to toothpick sequences</a>

%F a(n) = n^2-(n-1)^2*(1-(-1)^n)/8, if 0 <= n <=4.

%F Let b(n) = A194441(n), let c(n) = A194443(n), let d(n) = A010694(n), then:

%F Conjecture: a(n) = 4*(b(n-1)-d(n)) + 2*(c(n)-d(n+1)) + 2*(c(n+2)-d(n+1)) + 8, if n >= 3.

%F Conjecture: a(2^k+2) = 32, if k >= 3.

%e Written as a triangle:

%e 0,

%e 1,

%e 4,

%e 8,

%e 16,22,

%e 24,22,40,40,

%e 32,32,56,74,96,50,88,72,

%e 32,48,72,104,128,112,144,144,152,96,152,178,240,122,184,136,

%e 32,48,72,108,144,144,184,188,200,176,272,274,416,250,288,...

%Y Cf. A010694, A129370, A139250, A139251, A172311, A182839, A194270, A194441, A194443, A194445.

%K nonn

%O 0,3

%A _Omar E. Pol_, Aug 23 2011

%E More terms from Omar E. Pol, Sep 01 2011

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Last modified October 20 10:25 EDT 2019. Contains 328257 sequences. (Running on oeis4.)