%I A069944
%S A069944 1,1,1,3,12,60,180,630,10080,18144,453600,2494800,59875200,778377600,
%T A069944 1089728640,40864824000,1307674368000,22230464256000,15390321408000,
%U A069944 380140938777600,76028187755520000,1596591942865920000
%N A069944 Let b(1)=b(2)=1, b(n+2)=(1/(n+1))*(b(n+1)+b(n)); then a(n)=denominator(b(n)).
%C A069944 Sum(k=1,infinity,b(k))=e^(3/2) where e=2,718... More generally if b(1)=b(2)=...=b(m)=1 
               and b(n+m+1)=1/(n+m)*(b(n+m)+b(n+m-1)+...+b(n)) then Sum(k=1,infinity,
               b(k))=e^H(m) where H(m)=1+1/2+1/3+...+1/m is the m-th harmonic number 
               (Benoit Cloitre and Boris Gourevitch).
%Y A069944 Cf. A069943.
%Y A069944 A069943(n)/a(n) = A000085(n-1)/A000142(n-1) in lowest terms. (Christian 
               G. Bower, Jan 14 2006).
%Y A069944 Sequence in context: A114419 A090830 A127918 this_sequence A073996 A003483 
               A128602
%Y A069944 Adjacent sequences: A069941 A069942 A069943 this_sequence A069945 A069946 
               A069947
%K A069944 easy,frac,nonn
%O A069944 1,4
%A A069944 Benoit Cloitre (benoit7848c(AT)orange.fr), Apr 27 2002