Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A060546
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A060546 a(n) is the number of median-reflective (palindrome) symmetric patterns in a top-down equilateral triangular arrangement of closely packed black and white cells satisfying the local matching rule of Pascal's triangle modulo 2, where n is the number of cells in each edge of the arrangement. The matching rule is such that any elementary top-down triangle of three neighboring cells in the arrangement contains either one or three white cells. +0
8
2, 2, 4, 4, 8, 8, 16, 16, 32, 32, 64, 64, 128, 128, 256, 256, 512, 512, 1024, 1024, 2048, 2048, 4096, 4096, 8192, 8192, 16384, 16384, 32768, 32768, 65536, 65536, 131072, 131072, 262144, 262144, 524288, 524288, 1048576, 1048576, 2097152, 2097152 (list; graph; listen)
OFFSET

1,1

REFERENCES

A. Barb\'{e}, Symmetric patterns in the cellular automaton that generates Pascal's triangle modulo 2, Discr. Appl. Math. 105(2000), 1-38.

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,500

Index entries for sequences related to cellular automata

FORMULA

a(n) =2^ceil(n/2)

MAPLE

for n from 1 to 100 do printf(`%d, `, 2^ceil(n/2)) od:

PROGRAM

(PARI) { for (n=1, 500, write("b060546.txt", n, " ", 2^ceil(n/2)); ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 06 2009]

CROSSREFS

a(n)=A016116(n+1) for n >= 1 a(n)=2^A008619(n-1) for n >= 1

Adjacent sequences: A060543 A060544 A060545 this_sequence A060547 A060548 A060549

Sequence in context: A117575 A152166 A016116 this_sequence A163403 A120803 A000011

KEYWORD

easy,nice,nonn

AUTHOR

Andr\'{e} Barb\'{e} (Andre.Barbe(AT)esat.kuleuven.ac.be), Apr 03 2001

EXTENSIONS

More terms from James A. Sellers (sellersj(AT)math.psu.edu), Apr 04 2001

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified November 8 20:39 EST 2009. Contains 166234 sequences.


AT&T Labs Research