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 A020707 #48 Apr 02 2025 14:59:21 %S A020707 4,8,16,32,64,128,256,512,1024,2048,4096,8192,16384,32768,65536, %T A020707 131072,262144,524288,1048576,2097152,4194304,8388608,16777216, %U A020707 33554432,67108864,134217728,268435456,536870912,1073741824,2147483648,4294967296,8589934592 %N A020707 Pisot sequences E(4,8), L(4,8), P(4,8), T(4,8). %C A020707 Subsequence of A051916. - _Reinhard Zumkeller_, Mar 20 2010 %H A020707 Vincenzo Librandi, <a href="/A020707/b020707.txt">Table of n, a(n) for n = 0..238</a> %H A020707 Tanya Khovanova, <a href="http://www.tanyakhovanova.com/RecursiveSequences/RecursiveSequences.html">Recursive Sequences</a> %H A020707 <a href="/index/Di#divseq">Index to divisibility sequences</a> %H A020707 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (2). %F A020707 a(n) = 2^(n+2). %F A020707 a(n) = 2*a(n-1). %F A020707 G.f.: 4/(1-2*x). - _Philippe Deléham_, Nov 23 2008 %F A020707 E.g.f.: 4*exp(2*x). - _Stefano Spezia_, May 15 2021 %t A020707 2^(Range[0, 50] + 2) (* _Vladimir Joseph Stephan Orlovsky_, Jun 09 2011 *) %o A020707 (Magma) [2^(n+2): n in [0..40]]; // _Vincenzo Librandi_, Apr 28 2011 %o A020707 (PARI) a(n)=4<<n \\ _Charles R Greathouse IV_, Apr 08 2012 %o A020707 (Python) %o A020707 def A020707(n): return 1<<n+2 # _Chai Wah Wu_, Apr 02 2025 %Y A020707 Subsequence of A000079. See A008776 for definitions of Pisot sequences. %Y A020707 Cf. A051916. %K A020707 nonn,easy %O A020707 0,1 %A A020707 _David W. Wilson_