login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A256537 First differences of corner sequence A256536 associated with A151723. 3
1, 3, 5, 9, 9, 9, 17, 25, 17, 9, 17, 29, 37, 33, 41, 57, 33, 9, 17, 29, 37, 37, 53, 85, 85, 49, 41, 73, 101, 93, 101, 125, 65, 9, 17, 29, 37, 37, 53, 85, 85, 53, 53, 93, 133, 141, 149, 197, 181, 81, 41, 73, 101, 109, 141, 221, 253, 173, 117, 173, 249, 237, 237, 265, 129 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Number of cells turned ON at n-th stage in one of the outside corners of an infinite hexagon-shaped structure on hexagonal grid.

For an animation see "The movie version" in Links section.

LINKS

Table of n, a(n) for n=1..65.

David Applegate, The movie version

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to toothpick sequences

FORMULA

a(1) = 1; a(2) = 3.

It appears that a(n) = 1 + ((A151724(n) + A151724(n-1))/3, n >= 3.

It appears that a(n) = 1 + ((A151723(n) - A151723(n-2))/3, n >= 3.

It appears that a(n) = 1 + 2*(A170898(n-2) + A170898(n-3)), n >= 3.

a(3) = 5.

It appears that a(n) = 1 + 2*(A169779(n-2) - A169779(n-4)), n >= 4.

EXAMPLE

Written as an irregular triangle in which the row lengths are the absolute values of the terms of A141531, the sequence begins:

1;

3;

5;

9, 9;

9,17,25,17;

9,17,29,37,33,41,57,33;

9,17,29,37,37,53,85,85,49,41,73,101, 93,101,125, 65;

9,17,29,37,37,53,85,85,53,53,93,133,141,149,197,181,81,41,73,101,109,141,221,253,173,117,173,249,237,237,265,129;

...

It appears that the right border gives A083318, whose representation in base 2 gives A000533.

CROSSREFS

Cf. A000533, A083318, A141531, A151723, A151724, A169779, A170898, A256536.

Sequence in context: A176445 A292863 A160173 * A092996 A141264 A062949

Adjacent sequences:  A256534 A256535 A256536 * A256538 A256539 A256540

KEYWORD

nonn,tabf

AUTHOR

Omar E. Pol, Apr 02 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 10 16:56 EDT 2020. Contains 336381 sequences. (Running on oeis4.)