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 A158745 #11 Mar 12 2023 12:44:40
%S A158745 1,2,3,3,5,4,8,9,7,17,16,15,33,31,32,64,63,65,127,128,129,255,257,256,
%T A158745 512,513,511,1025,1024,1023,2049,2047,2048,4096,4095,4097,8191,8192,
%U A158745 8193,16383,16385,16384,32768,32769,32767,65537,65536,65535,131073,131071,131072,262144
%N A158745 a(3n)=A130750(n). a(3n+1)=A130752(n). a(3n+2)=A130755(n).
%C A158745 This mixes three sequences which are identical to their third differences.
%H A158745 Harvey P. Dale, <a href="/A158745/b158745.txt">Table of n, a(n) for n = 0..1000</a>
%H A158745 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 3, 0, 0, -3, 0, 0, 2).
%F A158745 a(3n)+a(3n+1)+a(3n+2)= A007283(n+1).
%F A158745 a(18n) = A130750(6n)= 2^(6n+1)-1.
%F A158745 a(n) = 3*a(n-3)-3*a(n-6)+2*a(n-9). G.f.: -(1+2*x+3*x^2-x^4-5*x^5+2*x^6+4*x^8)/((2*x^3-1)*(x^6-x^3+1)). - _R. J. Mathar_, Jan 23 2009
%t A158745 LinearRecurrence[{0,0,3,0,0,-3,0,0,2},{1,2,3,3,5,4,8,9,7},60] (* _Harvey P. Dale_, Mar 12 2023 *)
%Y A158745 Cf. A138635, A140430, A130785, A140495.
%K A158745 nonn,less
%O A158745 0,2
%A A158745 _Paul Curtz_, Mar 25 2009
%E A158745 Edited and extended by _R. J. Mathar_, Apr 09 2009