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A101699 Numbers n such that phi(n) = d_1*d_1!+d_2*d_2!+...+d_k*d_k! where d_1 d_2 ... d_k is the decimal expansion of n. 1
1, 23, 66666, 13179592 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
13179592 is in the sequence because phi(13179592) = 1*1!+3*3!+1*1!+7*7!+9*9!+5*5!+9*9!+2*2!.
MATHEMATICA
Do[If[Eulerphi[n] == Apply[Plus, IntegerDigits[n]*IntegerDigits[n]! ], Print[n]], {n, 30000000}]
Select[Range[132*10^5], EulerPhi[#]==Total[# #!&/@IntegerDigits[#]]&] (* Harvey P. Dale, Mar 06 2023 *)
CROSSREFS
Sequence in context: A233210 A173369 A185695 * A122148 A068736 A138763
KEYWORD
base,fini,nonn
AUTHOR
Farideh Firoozbakht, Dec 19 2004
STATUS
approved

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Last modified May 22 14:42 EDT 2024. Contains 372755 sequences. (Running on oeis4.)