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A323185 Denominators of rationals whose continued fraction representations show the prime factors of n (for n > 1) in nondecreasing order. 2
2, 3, 5, 5, 7, 7, 12, 10, 11, 11, 17, 13, 15, 16, 29, 17, 23, 19, 27, 22, 23, 23, 41, 26, 27, 33, 37, 29, 37, 31, 70, 34, 35, 36, 56, 37, 39, 40, 65, 41, 51, 43, 57, 53, 47, 47, 99, 50, 57, 52, 67, 53, 76, 56, 89, 58, 59, 59, 90, 61, 63, 73, 169, 66, 79, 67, 87 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

COMMENTS

a(n) is the denominator of the generating rational of n (see comments and numerators in A323184).

If n is prime, a(n) is n.

LINKS

Georg Fischer, Table of n, a(n) for n = 2..1000

EXAMPLE

a(28) = 37 because 15/37 = [0; 2, 2, 7] and 2*2*7 = 28.

a(29) = 29 because 1/29 = [0; 29] = 29.

MATHEMATICA

Array[Denominator@ FromContinuedFraction@ Prepend[Flatten@ Map[ConstantArray[#1, #2] & @@ # &, FactorInteger@ #], 0] &, 67, 2] (* Michael De Vlieger, Jan 07 2019 *)

PROG

(PARI) vectorise_factors(m)={v=[0]; F=factor(m); for(i=1, matsize(F)[1], for(j=1, F[i, 2], v=concat(v, F[i, 1]))); }

A323185(n)={vectorise_factors(n); contfracpnqn(v)[2, 1]; }

for(k=2, 75, print1(A323185(k)", "))

CROSSREFS

Cf. A323184.

Sequence in context: A082432 A336298 A037153 * A168065 A077724 A163867

Adjacent sequences: A323182 A323183 A323184 * A323186 A323187 A323188

KEYWORD

nonn,frac

AUTHOR

Chris Boyd, Jan 06 2019

STATUS

approved

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Last modified January 30 02:40 EST 2023. Contains 359939 sequences. (Running on oeis4.)