This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A132477 #10 Jun 29 2023 12:32:40
%S A132477 1,4,12,24,48,96,192,384,768,1536,3072,6144,12288,24576,49152,98304,
%T A132477 196608,393216,786432,1572864,3145728,6291456,12582912,25165824,
%U A132477 50331648,100663296,201326592,402653184,805306368,1610612736,3221225472,6442450944,12884901888
%N A132477 Row sums of triangle A132476.
%C A132477 A007283 = 3*2^n: (3, 6, 12, 24, 48, ...).
%H A132477 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (2).
%F A132477 a(0) = 1, a(1) = 4, a(n) = 3*2^n for n>1.
%F A132477 G.f.: -(1+2*x+4*x^2)/(-1+2*x). - _R. J. Mathar_, Nov 14 2007
%F A132477 a(n) = 2*a(n-1) for n>1. - _Harvey P. Dale_, May 31 2017
%e A132477 a(3) = 24 = sum of row 3 terms of triangle A132476: (3 + 7 + 13 + 1).
%t A132477 Join[{1,4},3 2^Range[2,40]] (* or *) Join[{1,4},NestList[2#&,12,40]] (* _Harvey P. Dale_, May 31 2017 *)
%Y A132477 Cf. A132476, A007283.
%K A132477 nonn
%O A132477 0,2
%A A132477 _Gary W. Adamson_, Aug 22 2007