A254060 a(n) is the denominator of the generalized continued fraction with terms sigma(m)/m for m=1 to n.

1, 5, 19, 37, 223, 297, 3863, 35359, 36845, 2160481, 2168207, 1246043, 65019169, 6514845019, 39336218671, 23752562695, 14840826739603, 99852376463843, 2194011687605077, 24037016781791473, 44229671263152569, 965358470386151983, 169222371166274070791

Offset

1,2

Links

Table of n, a(n) for n=1..23.

Example

The values of sigma(n)/n are: 1/1, 3/2, 4/3, 7/4, 6/5, ...
For n=1, the continued fraction is 1/1 so a(1)=1.
For n=2, it is 1/(1+3/2) = 2/5, so a(2)=5.
For n=3, it is 1/(1+3/(2+4/3)) = 10/19, so a(3)=19.

Prog

(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), ", "); ); }

Crossrefs

Cf. A017665 and A017666 (numerator and denominator of sigma(n)/n).

Cf. A254059 (denominators), A254061.

Sequence in context: A146861 A068963 A257929 * A129828 A239831 A146600

Adjacent sequences: A254057 A254058 A254059 * A254061 A254062 A254063

Keyword

nonn,frac

Author

Michel Marcus, Jan 24 2015

Status

approved