The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A161415 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A161415

First differences of A160414.
(history; published version)

#13 by N. J. A. Sloane at Wed Feb 24 02:48:18 EST 2021

LINKS

David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="http://neilsloane.com/docA000695/tootha000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]

Discussion

Wed Feb 24

02:48

OEIS Server: https://oeis.org/edit/global/2889

#12 by N. J. A. Sloane at Tue Nov 27 18:35:50 EST 2018

LINKS

David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="http://neilsloane.com/doc/tooth.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]

Discussion

Tue Nov 27

18:35

OEIS Server: https://oeis.org/edit/global/2774

#11 by Bruno Berselli at Fri Nov 17 08:45:01 EST 2017

STATUS

proposed

approved

#10 by Jean-François Alcover at Fri Nov 17 07:12:02 EST 2017

STATUS

editing

proposed

#9 by Jean-François Alcover at Fri Nov 17 07:11:55 EST 2017

MATHEMATICA

a[1] = 1; a[n_] := 4*3^DigitCount[n-1, 2, 1] - If[IntegerQ[Log[2, n]], 2n, 0];

Array[a, 60] (* Jean-François Alcover, Nov 17 2017, after N. J. A. Sloane *)

STATUS

approved

editing

#8 by Charles R Greathouse IV at Sat Sep 26 01:17:07 EDT 2015

LINKS

N. J. A. Sloane, <a href="http://neilsloane.com/docwiki/toothlist.htmlCatalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a>

Discussion

Sat Sep 26

01:17

OEIS Server: https://oeis.org/edit/global/2460

#7 by Charles R Greathouse IV at Tue Mar 11 01:34:14 EDT 2014

LINKS

O. Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/polca026.jpg">Illustration of initial terms</a> [From Omar E. Pol, Nov 11 2009]

D. Applegate, O. Omar E. Pol, N. J. A. Sloane, <a href="http://arxiv.org/abs/1004.3036">The toothpick sequence and other sequences from cellular automata</a>, arXiv:1004.3036 [math.CO] [From R. J. Mathar, Oct 16 2010]

Discussion

Tue Mar 11

01:34

OEIS Server: https://oeis.org/edit/global/2123

#6 by N. J. A. Sloane at Wed May 01 21:10:56 EDT 2013

FORMULA

For n > 1, a(n) = 4*A048883(n-1), except a(n) = 4*A048883(n-1) - 2n if n is a power of 2. - _N. J. A. Sloane, _, Jul 13 2009

Discussion

Wed May 01

21:10

OEIS Server: https://oeis.org/edit/global/1900

#5 by Charles R Greathouse IV at Thu Oct 04 10:29:10 EDT 2012

LINKS

David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="http://www.research.attneilsloane.com/~njas/doc/tooth.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>

N. J. A. Sloane, <a href="http://www.research.attneilsloane.com/~njas/doc/toothlist.html">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a>

Discussion

Thu Oct 04

10:29

OEIS Server: https://oeis.org/edit/global/1833

#4 by Russ Cox at Fri Mar 30 17:40:00 EDT 2012

LINKS

D. Applegate, O. E. Pol, N. J. A. Sloane, <a href="http://arxiv.org/abs/1004.3036">The toothpick sequence and other sequences from cellular automata</a>, arXiv:1004.3036 [math.CO] [From _R. J. Mathar (mathar(AT)strw.leidenuniv.nl), _, Oct 16 2010]

MAPLE

Contribution from _R. J. Mathar (mathar(AT)strw.leidenuniv.nl), _, Oct 16 2010: (Start)

EXTENSIONS

More terms from _R. J. Mathar (mathar(AT)strw.leidenuniv.nl), _, Oct 16 2010

Discussion

Fri Mar 30

17:40

OEIS Server: https://oeis.org/edit/global/190