[go: up one dir, main page]

login
A127613
a(n) = denominator of the continued fraction which has the positive divisors of n as its terms. The terms are written in order from n for the integer part, to 1 for the final term of the continued fraction.
2
1, 1, 1, 3, 1, 10, 1, 13, 4, 16, 1, 268, 1, 22, 21, 107, 1, 577, 1, 693, 29, 34, 1, 26512, 6, 40, 37, 1329, 1, 50323, 1, 1725, 45, 52, 43, 537559, 1, 58, 53, 113317, 1, 134368, 1, 3225, 2916, 70, 1, 10259608, 8, 4091, 69, 4485, 1, 282700, 67, 303277, 77, 88, 1
OFFSET
1,4
EXAMPLE
The divisors of 6 are 1,2,3,6. So a(6) is the denominator of 6 +1/(3 +1/(2+1/1)) = 63/10.
MATHEMATICA
f[n_] := Denominator[FromContinuedFraction[Reverse[Divisors[n]]]]; Table[f[n], {n, 60}] (* Ray Chandler, Jan 22 2007 *)
PROG
(PARI) a(n) = contfracpnqn(Vecrev(divisors(n)))[2, 1]; \\ Kevin Ryde, Jan 19 2023
CROSSREFS
Cf. A127611 (numerator), A127612.
Sequence in context: A010289 A226646 A347129 * A211360 A178866 A019427
KEYWORD
frac,nonn
AUTHOR
Leroy Quet, Jan 19 2007
EXTENSIONS
Extended by Ray Chandler, Jan 22 2007
STATUS
approved