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A161343 a(n) = 7^A000120(n). 2
1, 7, 7, 49, 7, 49, 49, 343, 7, 49, 49, 343, 49, 343, 343, 2401, 7, 49, 49, 343, 49, 343, 343, 2401, 49, 343, 343, 2401, 343, 2401, 2401, 16807, 7, 49, 49, 343, 49, 343, 343, 2401, 49, 343, 343, 2401, 343, 2401, 2401, 16807, 49, 343, 343, 2401, 343, 2401, 2401, 16807, 343, 2401, 2401, 16807, 2401, 16807, 16807, 117649 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Also first differences of A161342.

From Omar E. Pol, May 03 2015: (Start)

It appears that when A151785 is regarded as a triangle in which the row lengths are the powers of 2, this is what the rows converge to.

Also this is also a row of the square array A256140.

(End)

LINKS

Table of n, a(n) for n=0..63.

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

Index entries for sequences related to cellular automata

FORMULA

a(n) = A000420(A000120(n)). - Omar E. Pol, May 03 2015

G.f.: Product_{k>=0} (1 + 7*x^(2^k)). - Ilya Gutkovskiy, Mar 02 2017

EXAMPLE

From Omar E. Pol, May 03 2015: (Start)

Also, written as an irregular triangle in which the row lengths are the terms of A011782, the sequence begins:

1;

7;

7, 49;

7, 49, 49, 343;

7, 49, 49, 343, 49, 343, 343, 2401;

7, 49, 49, 343, 49, 343, 343, 2401, 49, 343, 343, 2401, 343, 2401, 2401, 16807;

...

Row sums give A055274.

Right border gives A000420.

(End)

PROG

(PARI) a(n) = 7^hammingweight(n); \\ Omar E. Pol, May 03 2015

CROSSREFS

Cf. A000420, A011782, A055274, A160410, A151785, A161411, A160428, A160429, A161342, A256140, A256141.

Rows of the array A256140 are: A000007, A000012, A001316, A048883, A102376, A256135, A256136, this sequence.

Sequence in context: A271064 A173294 A165828 * A038273 A245132 A222462

Adjacent sequences:  A161340 A161341 A161342 * A161344 A161345 A161346

KEYWORD

nonn

AUTHOR

Omar E. Pol, Jun 14 2009

EXTENSIONS

More terms from Sean A. Irvine, Mar 08 2011

New name from Omar E. Pol, May 03 2015

a(52)-a(63) from Omar E. Pol, May 16 2015

STATUS

approved

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Last modified September 28 09:32 EDT 2021. Contains 347714 sequences. (Running on oeis4.)