

A187211


First differences of A187210.


9



0, 1, 4, 7, 12, 22, 20, 22, 40, 54, 40, 22, 40, 54, 56, 70, 120, 134, 72, 22, 40, 54, 56, 70, 120, 134, 88, 70, 120, 150, 168, 246, 360, 326, 136, 22, 40, 54, 56, 70, 120, 134, 88, 70, 120, 150, 168, 246, 360, 326, 152, 70, 120, 150, 168, 246, 360, 342, 232, 246, 376, 454, 568, 838, 1032
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OFFSET

0,3


COMMENTS

Number of Qtoothpicks added at nth stage to the Qtoothpick structure of A187210.
For the connection with A139251, the first differences of the toothpick sequence A139250, see the Formula section.  Omar E. Pol, Apr 02 2016


LINKS

Nathaniel Johnston, Table of n, a(n) for n = 0..177
David Applegate, The movie version
David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata
Nathaniel Johnston, C script
Nathaniel Johnston, The QToothpick Cellular Automaton
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS


FORMULA

a(2^n + 2) = 16 + 8(2^(n1)  1), n >= 3. [Nathaniel Johnston, Mar 26 2011]
From Omar E. Pol, Apr 02 2016: (Start)
a(n) = floor(sqrt(2*n^3)), if 0<=n<=2 or n=6.
a(n) = 2*A139251(n2) + A267699(n2) + A267695(n1), if 3<=n<=5 or n>=7.
(End)


EXAMPLE

Written as an irregular triangle the sequence begins:
0;
1;
4;
7;
12;
22, 20;
22, 40, 54, 40;
22, 40, 54, 56, 70, 120, 134, 72;
22, 40, 54, 56, 70, 120, 134, 88, 70, 120, 150, 168, 246, 360, 326, 136;
...
The rows of this triangle tend to A188156.
From Omar E. Pol, Apr 02 2016: (Start)
For n = 5 we have that A139251(52) = 4, A267699(52) = 7 and A267695(51) = 7, so a(5) = 2*4 + 7 + 7 = 22.
For n = 10 we have that A139251(102) = 8, A267699(102) = 20 and A267695(101) = 4, so a(10) = 2*8 + 20 + 4 = 40.
(End)
Starting from a(3) = 7 the row lengths of triangle are the terms of A011782.  Omar E. Pol, Apr 04 2016


CROSSREFS

Cf. A011782, A139250, A139251, A172472, A182841, A187210, A187221, A267695, A267699.
Sequence in context: A117949 A228879 A010901 * A023624 A123194 A208668
Adjacent sequences: A187208 A187209 A187210 * A187212 A187213 A187214


KEYWORD

nonn,tabf


AUTHOR

Omar E. Pol, Mar 07 2011


EXTENSIONS

Terms after a(7) from Nathaniel Johnston, Mar 26 2011


STATUS

approved



