A112721 Numbers m such that phi(m) = d_1^1 + d_2^2 + ... + d_k^k where d_1 d_2 ... d_k is the decimal expansion of m.

1, 44, 84, 5676, 32186, 35097, 128476, 527048, 700298, 12141094, 43874279, 58730238, 303387848, 2277279428

Offset: 1

Author

Farideh Firoozbakht, Sep 17 2005

Keywords

• base
• fini
• more
• nonn

Comments

a(15) > 6*10^10. - Donovan Johnson, Nov 09 2010

All terms of this sequence are less than 2 * 10^42. - Charles R Greathouse IV, May 11 2012

a(15) > 10^12. - Giovanni Resta, Apr 12 2017

Examples

			phi(12141094) = 1^1 + 2^2 + 1^3 + 4^4 + 1^5 + 0^6 + 9^7 + 4^8 = 4848768 so 12141094 is in the sequence.
		

Crossrefs

Cf. A000010, A032799, A035138, A112718, A112719, A112720.

Programs

Mathematica

Do[d=IntegerDigits[n];k=Length[d];If[EulerPhi[n]==Sum[d[[j]]^j, {j, k}], Print[n]], {n, 30000000}]

Extensions

a(11)-a(12) from Farideh Firoozbakht, Jan 04 2009

a(13)-a(14) from Donovan Johnson, Nov 09 2010