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 A277757 #20 Feb 20 2025 12:53:34 %S A277757 2,128,8192,524288,33554432,2147483648,137438953472,8796093022208, %T A277757 562949953421312,36028797018963968,2305843009213693952, %U A277757 147573952589676412928,9444732965739290427392,604462909807314587353088,38685626227668133590597632 %N A277757 a(n) = 2^(6*n + 1). %C A277757 Additive digital root of a(n) = 2. %H A277757 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a>. %H A277757 <a href="http://oeis.org/index/Di#divseq">Index to divisibility sequences</a>. %H A277757 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (64). %F A277757 a(n) = 64*a(n-1). %F A277757 From _R. J. Mathar_, Dec 02 2016: (Start) %F A277757 G.f.: 2/(1-64*x). %F A277757 a(n) = 2*A089357(n). (End) %F A277757 From _Elmo R. Oliveira_, Feb 20 2025: (Start) %F A277757 E.g.f.: 2*exp(64*x). %F A277757 a(n) = A000079(A016921(n)). (End) %Y A277757 Cf. A000079, A016921, A089357. %K A277757 nonn,easy %O A277757 0,1 %A A277757 _Miquel Cerda_, Oct 28 2016