Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A141743
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A141743 Triangle read by rows T(n,k). Triangle elements are 0 and 1. Starting with 0 in the top add below a second row of (2n-1) elements (with n=2 -> 3). Moving from left to right add 0 if the number of adjacent 1's is odd or add 1 if it is even or null. See example below. +0
5
0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1 (list; graph; listen)
OFFSET

0,1

COMMENT

Any diagonal, read top down from right to left, expresses a periodic sequence of 0's and 1's Lengths of the periods are alway powers of 2. Here below the periods for the first 20 diagonals:

01

0

1100

1100

1110

0

00011110

10010110

00101000

00011110

10000100

01001000

00011010

1110

0101011110101000

1011000101001110

0111111011010100

1000100101110110

0111011101000100

1011010110000110

EXAMPLE

...............................0 First Row

............................1.... Add 1 to have an odd number of adjacent 1's

..............................0 First Row

............................1.0.. Add 0 because there is an odd number of adjacent 1's (second row)

..............................0 First Row

............................1.0.1 Again add 1 because thereis a null number of adjacent 1's.

The second row is now complete.

..............................0 First Row

............................1.0.1 Second Row

..........................0... Add 0 because there is only an 1 adjacent (second row)

..............................1 First Row

............................1.0.1 Second Row

..........................0.0.... Add 0 because there is only an 1 adjacent (second row)

.............................0 First Row

...........................1.0.1 Second Row

.........................0.0.1 Add 1 because there are two 1's adjacent (second row)

.............................0 First Row

...........................1.0.1 Second Row

.........................0.0.1.1 Add 1 because there are two 1's adjacent (second and third row)

.............................0 First Row

...........................1.0.1 Second Row

.........................0.0.1.1.1 Add 1 because there are two 1's adjacent (second and third row)

The third row is now complete. Then repeat the process for the other rows.

CROSSREFS

Adjacent sequences: A141740 A141741 A141742 this_sequence A141744 A141745 A141746

Sequence in context: A135993 A092202 A082848 this_sequence A112416 A061265 A125122

KEYWORD

easy,nonn

AUTHOR

Paolo P. Lava & Giorgio Balzarotti (ppl(AT)spl.at), Jul 07 2008

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 October 6 12:54 EDT 2008. Contains 144667 sequences.


AT&T Labs Research