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 A242072 #56 Feb 16 2025 08:33:22
%S A242072 3,1,8,2,4,8,1,5,8,4,0,5,8,4,4,8,6,9,4,2,5,9,6,2,0,2,7,4,8,1,4,0,6,9,
%T A242072 4,2,4,3,8,0,6,2,3,6,5,6,4,0,6,8,4,8,8,4,0,6,7,6,7,6,0,6,3,2,2,1,4,7,
%U A242072 6,7,3,0,9,2,5,7,5,8,7,9,1,0,3,9,7,4,5,6,9,5,4,1,9,5,2,5,5,7,0,3,7,4,5,3
%N A242072 Decimal expansion of the value of the continued fraction constructed from Mersenne primes.
%H A242072 Jean-Francois Alcover, <a href="/A242072/b242072.txt">Table of n, a(n) for n = 0..103</a>
%H A242072 C. K. Caldwell, <a href="http://www.utm.edu/research/primes/mersenne/index.html">Mersenne Primes</a>
%H A242072 Eric Weisstein's MathWorld, <a href="https://mathworld.wolfram.com/MersennePrime.html">Mersenne Prime</a>
%H A242072 Marek Wolf, <a href="http://arxiv.org/abs/1003.4015">"Continued fractions constructed from prime numbers"</a> arXiv:1003.4015 [math.NT] Sep 26 2010, p. 12.
%e A242072 0.318248158405844869425962027481406942438062365640684884...
%t A242072 (* The first 9 Mersenne primes suffice to get 104 correct digits *) MersennePrimes = Select[2^Prime[Range[18]] - 1, PrimeQ]; u = FromContinuedFraction[Join[{0}, MersennePrimes]]; RealDigits[u, 10, 104] // First
%Y A242072 Cf. A000043 (the main entry for this sequence), A028335, A000668, A247864.
%K A242072 nonn,cons
%O A242072 0,1
%A A242072 _Jean-François Alcover_, Oct 01 2014