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 A173995 #24 Apr 17 2022 09:26:18
%S A173995 0,1,1,2,9,1,3,5,1,2,1,1,1,1,3,1,7,1,31,1,2,4,5
%N A173995 Continued fraction expansion of sum of reciprocals of Fermat primes.
%C A173995 If there are only five Fermat primes, a(24) = 2 is the last term of this sequence. Otherwise, a(24) = a(25) = 1 and a(26) is large (billions of digits).
%C A173995 This sequence is finite if and only if A019434 is finite.
%D A173995 S. W. Golomb, Irrationality of the sum of reciprocals of fermat numbers and other functions, NASA Technical Report 19630013175, Accession ID 63N23055, Contract/grant NAS7-100, 4 pp., Jet Propulsion Laboratory, Jan 01 1962.
%F A173995 Continued fraction of Sum_{i >= 1} 1/A019434(i).
%e A173995 (1/3) + (1/5) + (1/17) + (1/257) + (1/65537) = 2560071829/4294967295 = 0 + 1/1+ 1/1+ 1/2+ 1/9+ 1/1+ 1/3+ 1/5+ 1/1+ 1/2+ 1/1+ 1/1+ 1/1+ 1/1+ 1/3+ 1/1+ 1/7+ 1/1+ 1/31+ 1/1+ 1/2+ 1/4+ 1/5+ 1/2.
%t A173995 (* Assuming 65537 is the largest Fermat prime *) ContinuedFraction[Sum[1/(2^(2^n) + 1), {n, 0, 4}]] (* _Alonso del Arte_, Apr 21 2013 *)
%Y A173995 Cf. A019434, A000215, A159611, A173898 (sum of reciprocals of Mersenne primes), A007400.
%K A173995 cofr,nonn,more
%O A173995 1,4
%A A173995 _Jonathan Vos Post_, Mar 04 2010
%E A173995 Sequence corrected and comments added by _Charles R Greathouse IV_, Feb 04 2011