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 A102650 #27 Mar 12 2024 12:56:43
%S A102650 4,12,28,56,116,236,476,952,1908,3820,7644,15288,30580,61164,122332,
%T A102650 244664,489332,978668,1957340,3914680,7829364,15658732,31317468,
%U A102650 62634936,125269876,250539756,501079516,1002159032,2004318068
%N A102650 a(n) = 4 * floor(28*2^n/15).
%C A102650 In binary, each term differs from the previous by a single bit.
%H A102650 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (2,0,0,1,-2).
%F A102650 G.f.: ( 4+4*x+4*x^2 ) / ( (x-1)*(2*x-1)*(1+x)*(x^2+1) ). - _R. J. Mathar_, Feb 20 2011
%p A102650 A102650:=n->4*floor(28*2^n/15); seq(A102650(n), n=0..40); # _Wesley Ivan Hurt_, Jan 21 2014
%t A102650 a[n_] := 4*Floor[28*2^n/15]; Table[a[n], {n, 0, 40}] (* _Stefan Steinerberger_, Apr 08 2006 *)
%t A102650 CoefficientList[Series[(4+4x+4x^2)/((x-1)(2x-1)(1+x)(x^2+1)), {x,0,45}],x] (* _Harvey P. Dale_, Mar 13 2011 *)
%o A102650 (PARI) a(n)=28<<n\15*4 \\ _Charles R Greathouse IV_, Feb 04 2016
%Y A102650 Cf. A102651, A102652, A102653.
%K A102650 easy,nonn,less
%O A102650 0,1
%A A102650 _Odimar Fabeny_, Feb 02 2005
%E A102650 Edited by _Don Reble_, Mar 28 2006
%E A102650 More terms from _Stefan Steinerberger_, Apr 08 2006