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 A228789 #16 Sep 17 2013 13:19:13
%S A228789 5,3,9,17,129,2049,262145,536870913,140737488355329,
%T A228789 75557863725914323419137,10633823966279326983230456482242756609,
%U A228789 803469022129495137770981046170581301261101496891396417650689
%N A228789 a(n) = 2^L(n) + 1, where L(n) is A000032(n).
%F A228789 a(n+2) = a(n)*a(n+1) - a(n) - a(n+1) + 2.
%F A228789 Binet type formula: log_2(a(n)-1) = r^n - s^n where r and s are the roots of x^2-x-1 = 0. (This is true the definition).
%t A228789 Table[1 + 2^LucasL[n], {n, 0, 11}] (* _T. D. Noe_, Sep 17 2013 *)
%Y A228789 Cf. A000032.
%K A228789 nonn,easy
%O A228789 0,1
%A A228789 M. Tamba and _Yeshwant Shivrai Valaulikar_, Sep 04 2013