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 A138702 #10 Dec 18 2018 17:04:20 %S A138702 1,2,2,1,2,1,2,1,2,1,3,1,6,1,2,1,7,1,7,1,4,1,4,1,6,1,2,1,6,1,7,1,7,1, %T A138702 2,1,10,1,2,1,8,1,2,1,3,1,5,1,10,1,3,1,7,1,7,1,6,1,6,1,17,1,2,1,7,1, %U A138702 10,1,2,1,7,1,23,1,2,1,2,1,5,1,18,1,5,1,16,1,2,1,10,1,14,1,6,1,2,1,18,1,2,1 %N A138702 a(n) = number of terms in the continued fraction of the absolute value of B_n, the n-th Bernoulli number. %C A138702 The continued fraction terms being counted include the initial 0, if there is one. (a(n), for all odd n >= 3, is 1.) %H A138702 Antti Karttunen, <a href="/A138702/b138702.txt">Table of n, a(n) for n = 0..16383</a> %e A138702 The 12th Bernoulli number is -691/2730. Now 691/2730 has the continued fraction 0 + 1/(3 + 1/(1 + 1/(19 + 1/(3 + 1/11)))), which has 6 terms (including the zero). So a(12) = 6. %o A138702 (PARI) %o A138702 lcf(x)=local(r);r=1;while(1,x-=floor(x);if(x==0,return(r));x=1/x;r++) %o A138702 a(n)=lcf(abs(bernfrac(n))) \\ _Franklin T. Adams-Watters_, May 14 2010 %Y A138702 Cf. A138701, A138703. %K A138702 nonn %O A138702 0,2 %A A138702 _Leroy Quet_, Mar 26 2008 %E A138702 More terms from _Franklin T. Adams-Watters_, May 14 2010