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%I #25 Nov 24 2024 17:11:14
%S 1,3,16,115,1281,16768,286337,5457171,125801270,3653694001,
%T 113390315301,4199095360138,172276300080959,7412079998841375,
%U 348540036245625584,18480034001016997327,1090670546096248467877,66549383345872173537824,4459899354719531875502085
%N Denominator of fraction equal to the continued fraction [ 2, 3, 5, ..., prime(n) ].
%F a(1) = 1, a(2) = 3, a(n) = A000040(n) * a(n-1) + a(n-2). - _Daniel Suteu_, Dec 20 2016
%e Prime(4) = 7, and 2+1/(3+1/(5+1/7)) = 266/115, so a(4) = 115. - _Jon E. Schoenfield_, Dec 20 2016
%o (PARI) a(n)=if(n<0,0,contfracpnqn(vector(n,i, prime(i)))[2,1])
%Y Cf. A000040, A036247.
%K frac,easy,nonn
%O 1,2
%A _Jeff Burch_
%E More terms from _Benoit Cloitre_, May 25 2003