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%I #10 Jun 29 2023 12:32:40
%S 1,4,12,24,48,96,192,384,768,1536,3072,6144,12288,24576,49152,98304,
%T 196608,393216,786432,1572864,3145728,6291456,12582912,25165824,
%U 50331648,100663296,201326592,402653184,805306368,1610612736,3221225472,6442450944,12884901888
%N Row sums of triangle A132476.
%C A007283 = 3*2^n: (3, 6, 12, 24, 48, ...).
%H <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (2).
%F a(0) = 1, a(1) = 4, a(n) = 3*2^n for n>1.
%F G.f.: -(1+2*x+4*x^2)/(-1+2*x). - _R. J. Mathar_, Nov 14 2007
%F a(n) = 2*a(n-1) for n>1. - _Harvey P. Dale_, May 31 2017
%e a(3) = 24 = sum of row 3 terms of triangle A132476: (3 + 7 + 13 + 1).
%t Join[{1,4},3 2^Range[2,40]] (* or *) Join[{1,4},NestList[2#&,12,40]] (* _Harvey P. Dale_, May 31 2017 *)
%Y Cf. A132476, A007283.
%K nonn
%O 0,2
%A _Gary W. Adamson_, Aug 22 2007