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A082059
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Numbers k such that k, sigma(k) and phi(k) have the same decimal digits.
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2
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1, 1021, 1201, 2011, 7687, 7867, 8677, 10211, 10271, 10321, 12011, 12041, 12071, 12101, 12301, 12343, 12401, 12433, 12601, 14323, 16787, 17021, 20011, 20101, 20161, 20411, 20611, 21001, 21011, 21031, 21061, 21101, 21401, 21433, 21601, 21701, 22343, 22433
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OFFSET
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1,2
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LINKS
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Donovan Johnson, Table of n, a(n) for n = 1..1000
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EXAMPLE
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n = 89767, sigma(n) = 89768, phi(n) = 89766.
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MATHEMATICA
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Select[Range[25000], Union[IntegerDigits[#]] == Union[ IntegerDigits[ DivisorSigma[ 1, #]]] == Union[IntegerDigits[EulerPhi[#]]]&] (* Harvey P. Dale, Jun 12 2014 *)
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PROG
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(PARI) c=0; for(n=1, 324773, m=n; nd=vector(10); for(j=1, 6, r=m%10; nd[r+1]=1; m=m\10; if(m==0, j=6)); s=sigma(n); m=s; sd=vector(10); for(j=1, 6, r=m%10; sd[r+1]=1; m=m\10; if(m==0, j=6)); for(j=1, 10, if(nd[j]<>sd[j], next(2))); p=eulerphi(n); m=p; pd=vector(10); for(j=1, 6, r=m%10; pd[r+1]=1; m=m\10; if(m==0, j=6)); for(j=1, 10, if(nd[j]<>pd[j], next(2))); c++; write("b082059.txt", c " " n)) \\ Donovan Johnson, Feb 28 2013
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CROSSREFS
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Cf. A000203 (sigma), A000010 (phi).
Sequence in context: A209620 A179032 A179033 * A081633 A020388 A306596
Adjacent sequences: A082056 A082057 A082058 * A082060 A082061 A082062
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KEYWORD
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nonn,base
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AUTHOR
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Labos Elemer, Apr 04 2003
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STATUS
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approved
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