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A083367 Numbers k that are equal to the sum of its divisors after the digits of each divisor have been sorted in ascending order. 0
1, 60, 1959, 149587, 277947, 1449933, 2222863, 2396214, 24918486, 25354845, 48878262, 1673533845, 24753647943 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
No more terms through 10^8. - Ryan Propper, Sep 09 2005
a(13) > 10^10. - Donovan Johnson, Aug 28 2013
a(14) > 10^11. - Giovanni Resta, Aug 30 2013
LINKS
EXAMPLE
a(3) = 1959 because the divisors of 1959 are [1, 3, 653, 1959] and 1+3+356+1599 = 1959.
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 *)
PROG
(PARI) is(n) = sumdiv(n, d, fromdigits(vecsort(digits(d))))==n \\ David A. Corneth, Dec 28 2022
(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
CROSSREFS
Cf. A004185.
Sequence in context: A058836 A166792 A013925 * A173123 A004353 A269284
KEYWORD
nonn,base,more
AUTHOR
Jason Earls, Jun 11 2003
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
STATUS
approved

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Last modified March 29 09:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)