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 A195464 #32 Mar 28 2024 13:19:04 %S A195464 13,139,2083,32899,524803,8390659,134225923,2147516419,34359869443, %T A195464 549756338179,8796095119363,140737496743939,2251799847239683, %U A195464 36028797153181699,576460752840294403,9223372039002259459,147573952598266347523,2361183241469182345219 %N A195464 a(n) = 2^(4*n + 3) + 2*4^n + 3. %C A195464 Binary numbers of form 1j1i11 where j and i are the number of 0's, n is the index, i = 2*n+1, j = 2*n+3. %H A195464 Vincenzo Librandi, <a href="/A195464/b195464.txt">Table of n, a(n) for n = 0..800</a> %H A195464 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (21,-84,64). %F A195464 a(n) = 2^(4*n+3) + A188161(n). %F A195464 From _Alexander R. Povolotsky_, Sep 19 2011: (Start) %F A195464 a(n+2) = 20*a(n+1) - 64*a(n) + 135. %F A195464 G.f.: (-13 + 134*x - 256*x^2)/(-1 + 21*x - 84*x^2 + 64*x^3). (End) %F A195464 a(n) = 3 + A026244(n+1). - _Bruno Berselli_, Sep 19 2011 %e A195464 Terms starting from n=1 written in binary are 10001011, 100000100011, 1000000010000011, 10000000001000000011. %o A195464 (Magma) [2^(4*n + 3) + 2*4^n + 3: n in [0..20]]; // _Vincenzo Librandi_, Sep 30 2011 %Y A195464 Cf. A188161. %K A195464 nonn,easy %O A195464 0,1 %A A195464 _Brad Clardy_, Sep 19 2011