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A114065 Numbers k such that the digits of phi(k) and sigma(k) are permutations of those of k. 5
1, 3014685, 21638943, 170726121, 207380169, 215341083, 233559801, 234511083, 321634251, 1620475083, 1982243007, 2019804093, 2084013063, 2185499607, 2410658685, 2653713819, 2741018409, 2859457041, 3018792645, 3075268041, 3148920504, 3701484126, 4071408255 (list; graph; refs; listen; history; text; internal format)
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

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Last modified January 18 06:55 EST 2022. Contains 350454 sequences. (Running on oeis4.)