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A074256 Sum of factorials of digits of n equals sum of the primes from the smallest prime factor of n to the largest prime factor of n. 0

%I #18 Mar 01 2023 13:59:57

%S 2,242,1323,3200,13050,30000,42432,132300,426205,442244,620425,665353,

%T 1261645,1306254,1453032,1461363,1523340,1523466,2025012,2105334,

%U 2134350,2205102,2613504,2713421,3005264,3312400,3314520,3432000

%N Sum of factorials of digits of n equals sum of the primes from the smallest prime factor of n to the largest prime factor of n.

%e 242 = 2*11^2 and 2+3+5+7+11 = 28 and 2!+4!+2! = 28.

%t okQ[n_]:=Module[{ifn=Transpose[FactorInteger[n]][[1]]}, Total[Prime[ Range[ PrimePi[ Min[ifn]], PrimePi[Max[ifn]]]]]==Total[IntegerDigits[n]!]]; Select[Range[ 2,3500000],okQ] (* _Harvey P. Dale_, Apr 21 2011 *)

%Y Cf. A074036.

%K nonn,base

%O 0,1

%A _Jason Earls_, Sep 20 2002

%E More terms from _Michel ten Voorde_, Jun 20 2003

%E More terms from _Sam Alexander_, Feb 28 2005

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Last modified March 28 07:30 EDT 2024. Contains 371235 sequences. (Running on oeis4.)