A102018 Numbers n>1 with the property that the decimal expansion of n is a permutation of the digits of the decimal expansion of phi(n) and the ratio n/phi(n) is a new record low value.

21, 291, 2817, 2991, 4435, 20617, 45421, 69271, 75841, 162619, 176569, 284029, 400399, 474883, 732031, 778669, 783169, 1014109, 1288663, 1504051, 1514419, 1924891, 1956103, 2006737, 2044501, 2094901, 2239261, 2710627, 2868469, 3582907, 3689251, 4198273, 4696009

Offset: 1

Author

Gunnar Arn Stefainsson (gos(AT)hell.is), Jun 19 2007

Keywords

• nonn
• base

Comments

Subsequence of A115921. - Michel Marcus, Jul 10 2015

Links

• Project Euler, Problem 70: Investigate values of n for which phi(n) is a permutation of n.

Crossrefs

Cf. A000010, A115921.

Programs

PARI

lista(nn) = {mre = 2; for (n=2, nn, en = eulerphi(n); if (vecsort(digits(n)) == vecsort(digits(en)), re = n/en; if (re < mre, print1(n, ", "); mre = re);););} \\ Michel Marcus, Jul 10 2015

Extensions

More terms from Michel Marcus, Jul 10 2015

Removed initial 1 and changed definition, following discussion in Sequence Fans Mailing List by Michel Marcus and others. - N. J. A. Sloane, Jul 15 2015