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, 23, 66666, 13179592

Offset

1,2

Links

Table of n, a(n) for n=1..4.

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

Cf. A101697, A101698.

Sequence in context: A233210 A173369 A185695 * A122148 A068736 A138763

Adjacent sequences: A101696 A101697 A101698 * A101700 A101701 A101702

Keyword

base,fini,nonn

Author

Farideh Firoozbakht, Dec 19 2004

Status

approved