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.

Previous Showing 11-14 of 14 results.

A194800 Number of grid points that are covered after n-th stage of A139250, assuming the vertical toothpicks have length 2 and the horizontal toothpicks have length 4.

Original entry on oeis.org

0, 3, 11, 17, 31, 39, 67
Offset: 0

Views

Author

Omar E. Pol, Sep 07 2011

Keywords

Comments

There are an infinite family of these sequences since A139250 gives the number of toothpicks in the structure regardless of the length difference between horizontal toothpicks and vertical toothpicks. Examples: A147614, this sequence, A194802, A160420, etc.

Examples

			a(2) = 11.
o o o o o
. . o . .
o o o o o
		

Crossrefs

A194802 Number of grid points that are covered after n-th stage of A139250, assuming the vertical toothpicks have length 4 and the horizontal toothpicks have length 2.

Original entry on oeis.org

0, 5, 9, 23, 29, 45, 57
Offset: 0

Views

Author

Omar E. Pol, Sep 07 2011

Keywords

Comments

There are an infinite family of these sequences since A139250 gives the number of toothpicks in the structure regardless of the length difference between horizontal toothpicks and vertical toothpicks. Examples: A147614, A194800, this sequence, A160420, etc.

Examples

			a(2) = 9.
o o o
. o .
. o .
. o .
o o o
		

Crossrefs

A162627 a(n) = A162625(n+1)/2.

Original entry on oeis.org

2, 3, 3, 4, 6, 7, 5, 4, 6, 8, 10, 14, 18, 17, 9, 4, 6, 8, 10, 14, 18, 18, 14, 14, 20, 26, 34, 46, 52, 41, 17, 4, 6, 8, 10, 14, 18, 18, 14, 14, 20, 26, 34, 46, 52, 42, 22, 14, 20, 26, 34, 46, 54, 50, 42, 48, 66, 86, 114, 144, 144, 97, 33, 4, 6, 8, 10, 14, 18, 18
Offset: 1

Views

Author

Omar E. Pol, Aug 05 2009

Keywords

Crossrefs

Extensions

More terms from Jinyuan Wang, Mar 03 2020

A210985 Number of segments needed to draw the toothpick structure of A139250 as it is after 2^n stages.

Original entry on oeis.org

1, 3, 7, 19, 63, 235, 919, 3651, 14575
Offset: 0

Views

Author

Omar E. Pol, Sep 11 2012

Keywords

Comments

It appears that this is also the partial sums of A039301.
It appears that this is also 1 together with A160128.

Examples

			For n = 3, after 2^3 stages the toothpick structure of A139250 contains 43 toothpicks (A139250(2^3) = 43). However the toothpick structure can be essentially represented by 19 segments (A139252(2^3) = 19), so a(3) = 19.
		

Crossrefs

Formula

a(n) = A139252(2^n).
Previous Showing 11-14 of 14 results.