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A074257 Sum of factorials of digits of n equals the largest prime factor of n. 2
2, 12, 341, 403, 1200, 1232, 2000, 2204, 4530, 4614, 5134, 10000, 13200, 13345, 14210, 21141, 23100, 31433, 40020, 101442, 111252, 111452, 112000, 112320, 123201, 135453, 145343, 162121, 173434, 200025, 202106, 203050, 210000, 211420 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (first 250 terms from Librandi)

EXAMPLE

4614 = 2*3*769 and 4!+6!+1!+4! = 769.

MATHEMATICA

Select[Range[220000], FactorInteger[#][[-1, 1]]==Total[IntegerDigits[#]!]&] (* Harvey P. Dale, Mar 08 2014 *)

PROG

(PARI) gpf(n)=if(n<2, 1, my(f=factor(n)[, 1]); f[#f])

is(n)=my(d=digits(n), t=sum(i=1, #d, d[i]!)); n%t==0&&isprime(t)&&gpf(n/t)<=t \\ Charles R Greathouse IV, Mar 10 2014

CROSSREFS

Cf. A061602.

Sequence in context: A181142 A088229 A060596 * A192892 A105231 A009398

Adjacent sequences:  A074254 A074255 A074256 * A074258 A074259 A074260

KEYWORD

base,nonn

AUTHOR

Jason Earls, Sep 20 2002

STATUS

approved

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Last modified January 22 19:16 EST 2020. Contains 331153 sequences. (Running on oeis4.)