cp's OEIS Frontend

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.

A220811 Numerators of the Verhulst sequence x(n+1)=4*x(n)-3*x(n)^2, x(0)=1/10.

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%I A220811 #11 Feb 16 2025 08:33:18
%S A220811 1,37,10693,84699253,12357810823725973,
%T A220811 36165967884042486031784215609813,
%U A220811 10542455454648216809579521558960739092388747823498758873614315093
%N A220811 Numerators of the Verhulst sequence x(n+1)=4*x(n)-3*x(n)^2, x(0)=1/10.
%D A220811 H. O. Peitgen and P. H. Richter, The Beauty of Fractals. Springer, 1986, p. 23f.
%H A220811 Reinhard Zumkeller, <a href="/A220811/b220811.txt">Table of n, a(n) for n = 0..9</a>
%H A220811 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LogisticEquation.html">Logistic Equation</a>
%H A220811 Wikipedia, <a href="http://en.wikipedia.org/wiki/Logistic_map">Logistic map</a>
%o A220811 (Haskell)
%o A220811 import Data.Ratio ((%), numerator)
%o A220811 a220811 n = a220811_list !! n
%o A220811 a220811_list = map numerator vs where
%o A220811    vs = iterate (\x -> x * (4 - 3 * x)) (1 % 10)
%o A220811 -- _Reinhard Zumkeller_, Dec 22 2012
%Y A220811 Cf. A051840, A220812 (denominators).
%K A220811 nonn,frac
%O A220811 0,2
%A A220811 _Reinhard Zumkeller_, Dec 22 2012