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%I #4 Jan 24 2015 15:50:50
%S 1,5,19,37,223,297,3863,35359,36845,2160481,2168207,1246043,65019169,
%T 6514845019,39336218671,23752562695,14840826739603,99852376463843,
%U 2194011687605077,24037016781791473,44229671263152569,965358470386151983,169222371166274070791
%N a(n) is the denominator of the generalized continued fraction with terms sigma(m)/m for m=1 to n.
%e The values of sigma(n)/n are: 1/1, 3/2, 4/3, 7/4, 6/5, ...
%e For n=1, the continued fraction is 1/1 so a(1)=1.
%e For n=2, it is 1/(1+3/2) = 2/5, so a(2)=5.
%e For n=3, it is 1/(1+3/(2+4/3)) = 10/19, so a(3)=19.
%o (PARI) a(nn) = {my(v = vector(nn, n, sigma(n)/n)); for (n=1, nn, val = v[n]; forstep(k=n-1, 1, -1, val = numerator(v[k])/(denominator(v[k]) + val);); print1(denominator(val), ", "););}
%Y Cf. A017665 and A017666 (numerator and denominator of sigma(n)/n).
%Y Cf. A254059 (denominators), A254061.
%K nonn,frac
%O 1,2
%A _Michel Marcus_, Jan 24 2015