A161343 a(n) = 7^A000120(n).

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

Offset: 0

Author

Omar E. Pol, Jun 14 2009

Keywords

• nonn

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)

Examples

			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)
		

Links

• N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
• Index entries for sequences related to cellular automata

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.

Programs

PARI

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

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

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