

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
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OFFSET

1,2


COMMENTS

Number of cells turned ON at nth stage in one of the outside corners of an infinite hexagonshaped 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(n1))/3, n >= 3.
It appears that a(n) = 1 + ((A151723(n)  A151723(n2))/3, n >= 3.
It appears that a(n) = 1 + 2*(A170898(n2) + A170898(n3)), n >= 3.
a(3) = 5.
It appears that a(n) = 1 + 2*(A169779(n2)  A169779(n4)), 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



