cp's OEIS Frontend

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

%I A161343 #25 Mar 02 2017 05:43:27
%S A161343 1,7,7,49,7,49,49,343,7,49,49,343,49,343,343,2401,7,49,49,343,49,343,
%T A161343 343,2401,49,343,343,2401,343,2401,2401,16807,7,49,49,343,49,343,343,
%U A161343 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
%N A161343 a(n) = 7^A000120(n).
%C A161343 Also first differences of A161342.
%C A161343 From _Omar E. Pol_, May 03 2015: (Start)
%C A161343 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.
%C A161343 Also this is also a row of the square array A256140.
%C A161343 (End)
%H A161343 N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a>
%H A161343 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a>
%F A161343 a(n) = A000420(A000120(n)). - _Omar E. Pol_, May 03 2015
%F A161343 G.f.: Product_{k>=0} (1 + 7*x^(2^k)). - _Ilya Gutkovskiy_, Mar 02 2017
%e A161343 From _Omar E. Pol_, May 03 2015: (Start)
%e A161343 Also, written as an irregular triangle in which the row lengths are the terms of A011782, the sequence begins:
%e A161343 1;
%e A161343 7;
%e A161343 7, 49;
%e A161343 7, 49, 49, 343;
%e A161343 7, 49, 49, 343, 49, 343, 343, 2401;
%e A161343 7, 49, 49, 343, 49, 343, 343, 2401, 49, 343, 343, 2401, 343, 2401, 2401, 16807;
%e A161343 ...
%e A161343 Row sums give A055274.
%e A161343 Right border gives A000420.
%e A161343 (End)
%o A161343 (PARI) a(n) = 7^hammingweight(n); \\ _Omar E. Pol_, May 03 2015
%Y A161343 Cf. A000420, A011782, A055274, A160410, A151785, A161411, A160428, A160429, A161342, A256140, A256141.
%Y A161343 Rows of the array A256140 are: A000007, A000012, A001316, A048883, A102376, A256135, A256136, this sequence.
%K A161343 nonn
%O A161343 0,2
%A A161343 _Omar E. Pol_, Jun 14 2009
%E A161343 More terms from _Sean A. Irvine_, Mar 08 2011
%E A161343 New name from _Omar E. Pol_, May 03 2015
%E A161343 a(52)-a(63) from _Omar E. Pol_, May 16 2015