A114065 Numbers k such that the digits of phi(k) and sigma(k) are permutations of those of k.

1, 3014685, 21638943, 170726121, 207380169, 215341083, 233559801, 234511083, 321634251, 1620475083, 1982243007, 2019804093, 2084013063, 2185499607, 2410658685, 2653713819, 2741018409, 2859457041, 3018792645, 3075268041, 3148920504, 3701484126, 4071408255

Offset: 1

Author

Giovanni Resta, Feb 13 2006

Keywords

• nonn
• base

Comments

Intersection of A115920 and A115921.

Examples

			sigma(3014685) = 5431680 and phi(3014685) = 1586304.
		

Links

• Giovanni Resta, Table of n, a(n) for n = 1..520 (terms < 10^12)

Crossrefs

Cf. A115920, A115921, A175795.

Cf. A000010, A000203.

Programs

PARI

isok(n) = (d = vecsort(digits(n))) && (ds = vecsort(digits(sigma(n)))) && (d == ds) && (de = vecsort(digits(eulerphi(n)))) && (ds == de); \\ Michel Marcus, Dec 13 2015

Python

from sympy import totient, divisor_sigma
A114065_list = [n for n in range(1,10**7) if sorted(str(divisor_sigma(n))) == sorted(str(totient(n))) == sorted(str(n))] # Chai Wah Wu, Dec 13 2015