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

1,2

Comments

Intersection of A115920 and A115921.

Links

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

Example

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

Prog

(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
(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

Crossrefs

Cf. A115920, A115921, A175795.

Cf. A000010, A000203.

Sequence in context: A043656 A027666 A224077 * A268405 A187438 A184374

Adjacent sequences: A114062 A114063 A114064 * A114066 A114067 A114068

Keyword

nonn,base

Author

Giovanni Resta, Feb 13 2006

Status

approved