cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-4 of 4 results.

A160730 Toothpick sequence starting from a right angle formed by two toothpicks.

Original entry on oeis.org

0, 2, 4, 8, 14, 20, 26, 38, 52, 64, 70, 82, 96, 112, 130, 162, 196, 216, 222, 234, 248, 264, 282, 314, 348, 372, 390, 422, 460, 504, 566, 658, 740, 776, 782, 794, 808, 824, 842, 874, 908, 932, 950, 982, 1020, 1064
Offset: 0

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Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

Terms after a(11) from Nathaniel Johnston, Mar 28 2011

A323647 Number of elements added at n-th stage to the toothpick structure of A323646.

Original entry on oeis.org

1, 2, 2, 4, 6, 6, 6, 12, 14, 12, 6, 12, 14, 16, 18, 32, 34, 20, 6, 12, 14, 16, 18, 32, 34, 24, 18, 32, 38, 44, 62, 92, 82, 36, 6, 12, 14, 16, 18, 32, 34, 24, 18, 32, 38, 44, 62, 92, 82, 40, 18, 32, 38, 44, 62, 92, 86, 60, 62, 96, 114, 144, 210, 260, 194, 68, 6, 12, 14, 16, 18, 32, 34, 24, 18, 32, 38, 44, 62, 92
Offset: 1

Views

Author

Omar E. Pol, Mar 07 2019

Keywords

Comments

The "word" of this cellular automaton is "ab", but note that this triangle has an unusual structure: an additional row of length 2. For more information about the word of cellular automata see A296612.
The structure of the irregular triangle is as shown below:
a,b;
a,b;
a,b;
a,b,a,b;
a,b,a,b,a,b,a,b;
a,b,a,b,a,b,a,b,a,b,a,b,a,b,a,b;
...
Row lengths give 2 together with the terms of A011782 multiplied by 2, also 2 togheter with the column 2 of A296612.
Columns "a" contain numbers of toothpicks of length 2.
Columns "b" contain numbers of D-toothpicks of length 2*sqrt(2). See the example.

Examples

			Triangle begins:
1, 2;
2, 4;
6, 6;
6,12,14,12;
6,12,14,16,18,32,34,20;
6,12,14,16,18,32,34,24,18,32,38,44,62,92,82,36;
6,12,14,16,18,32,34,24,18,32,38,44,62,92,82,40,18,32,38,44,62,92,86,60,62,96, ...
		

Crossrefs

First differences of A323646.
Also, 1 together with A160731.
Column 1 gives A134201.
For other hybrid cellular automata, see A194271, A194701, A220501, A289841, A290221, A294021, A294963, A294981, A299771, A323651, A327331, A327333.

A160733 First differences of A160732.

Original entry on oeis.org

3, 3, 6, 8, 8, 6, 12, 14, 8, 8, 16, 20, 18, 18, 30, 26, 8, 8, 16, 20, 18, 20, 34, 32, 20, 28, 48, 54, 50, 60, 78, 50, 8, 8, 16, 20, 18, 20, 34, 32, 20, 28, 48, 54, 50, 62, 82, 56, 20, 28, 48, 54, 52, 70, 96
Offset: 1

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

Terms after a(9) from Nathaniel Johnston, Mar 30 2011

A168113 First differences of A168112.

Original entry on oeis.org

1, 1, 2, 3, 3, 3, 6, 7, 6, 3, 6, 7, 8, 9, 16, 17, 10, 3, 6, 7, 8, 9, 16, 17, 12, 9, 16, 19, 22, 31, 46, 41, 18, 3, 6, 7, 8, 9, 16, 17, 12, 9, 16, 19, 22, 31, 46, 41, 20, 9, 16, 19, 22, 31, 46, 43, 30, 31, 48
Offset: 1

Views

Author

Omar E. Pol, Dec 07 2009

Keywords

Comments

a(n) is the number of toothpicks added at the n-th round in the toothpick structure of A168112.

Examples

			If written as a triangle, begins:
1;
1;
2;
3,3;
3,6,7,6;
3,6,7,8,9,16,17,10;
3,6,7,8,9,16,17,12,9,16,19,22,31,46,41,18;
Rows converge to A168114.
		

Crossrefs

Formula

Observation: It appears that a(2^i+2) = 3, for i>0.
a(n) = A160731(n)/2. [From Nathaniel Johnston, Mar 28 2011]

Extensions

Terms after a(34) from Nathaniel Johnston, Mar 28 2011
Showing 1-4 of 4 results.