A083367 Numbers k that are equal to the sum of its divisors after the digits of each divisor have been sorted in ascending order.
1, 60, 1959, 149587, 277947, 1449933, 2222863, 2396214, 24918486, 25354845, 48878262, 1673533845, 24753647943
Offset: 1
Examples
a(3) = 1959 because the divisors of 1959 are [1, 3, 653, 1959] and 1+3+356+1599 = 1959.
Crossrefs
Cf. A004185.
Programs
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Mathematica
Do[l = IntegerDigits /@ Divisors[n]; l = Map[Sort[ # ]&, l]; k = Plus @@ Map[FromDigits[ # ]&, l]; If[k == n, Print[n]], {n, 1, 10^8}] (* Ryan Propper, Sep 09 2005 *) Select[Range[24*10^5],Total[FromDigits[Sort[IntegerDigits[#]]]&/@Divisors[#]] == #&] (* The program generates the first 8 terms of the sequence. *) (* Harvey P. Dale, Dec 28 2022 *) -
PARI
is(n) = sumdiv(n,d,fromdigits(vecsort(digits(d))))==n \\ David A. Corneth, Dec 28 2022
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Python
from sympy import divisors def sa(n): return int("".join(sorted(str(n)))) def ok(n): return n == sum(sa(d) for d in divisors(n, generator=True)) print([k for k in range(1, 3*10**5) if ok(k)]) # Michael S. Branicky, Dec 28 2022
Extensions
More terms from Ryan Propper, Sep 09 2005
a(12) from Donovan Johnson, Aug 28 2013
a(13) from Giovanni Resta, Aug 30 2013
Comments