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.

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

Links

Crossrefs

Cf. A139250, A147614, A162795, A162796, A162797, A175098, A160420, A160422, A194802.

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

Links

Crossrefs

Cf. A139250, A147614, A162795, A162796, A162797, A175098, A160420, A160422, A194800

A160018 A175099 with a(3) changed from 0 to 1.

Original entry on oeis.org

0, 0, 0, 1, 1, 0, 0, 2, 3, 0, 0, 2, 2, 0, 0, 4, 7, 0, 0, 2, 2, 0, 0, 4, 6, 0, 0, 4, 4, 0, 0, 8, 15, 0, 0, 2, 2, 0, 0, 4, 6, 0, 0, 4, 4, 0, 0, 8, 14, 0, 0, 4, 4, 0, 0, 8, 12, 0, 0, 8, 8, 0, 0, 16, 31, 0, 0, 2, 2, 0, 0, 4, 6, 0, 0, 4, 4, 0, 0, 8, 14, 0, 0, 4, 4, 0, 0, 8, 12, 0, 0, 8, 8, 0, 0, 16, 30, 0, 0, 4, 4, 0
Offset: 0

Views

Author

N. J. A. Sloane, Feb 07 2010

Keywords

Links

Crossrefs

Cf. A160125, A175098, A175099.

Formula

a(n) = a(1) = 0; for k >= 1, a(2^k) = 2^(k-1)-1, a(2^k+i) = 2*a(i) for 1 <= i < 2^k.

A175099 Number of closed rectangles added at the n-th stage of the leftist toothpicks A151566.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 0, 2, 3, 0, 0, 2, 2, 0, 0, 4, 7, 0, 0, 2, 2, 0, 0, 4, 6, 0, 0, 4, 4, 0, 0, 8, 15, 0, 0, 2, 2, 0, 0, 4, 6, 0, 0, 4, 4, 0, 0, 8, 14, 0, 0, 4, 4, 0, 0, 8, 12, 0, 0, 8, 8, 0, 0, 16, 31, 0, 0, 2, 2, 0, 0, 4, 6, 0, 0, 4, 4, 0, 0, 8, 14, 0, 0, 4, 4, 0, 0, 8, 12, 0, 0, 8, 8, 0, 0, 16, 30, 0, 0, 4, 4, 0
Offset: 0

Views

Author

R. J. Mathar, Feb 04 2010

Keywords

Links

Crossrefs

Cf. A160125, A175098

Formula

For a recurrence see A160018. - N. J. A. Sloane, Feb 07 2010
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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