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A217301
Numbers n such that gcd(n, phi(n)) = gcd(phi(n), sigma(n)) = gcd(sigma(n), n) = tau(n).
2
1, 184, 376, 1336, 1912, 2104, 2872, 3064, 3832, 4024, 4792, 5176, 5752, 5944, 6712, 6904, 7096, 7864, 8824, 9784, 10552, 10936, 11512, 11896, 12472, 12664, 12856, 14584, 14776, 16312, 16504, 16696, 17656, 19192, 19384, 19576, 20344, 21304, 21496, 22644
OFFSET
1,2
LINKS
MATHEMATICA
Select[Range[20000], GCD[#, EulerPhi[#]] == GCD[EulerPhi[#], DivisorSigma[1, #]] == GCD[#, DivisorSigma[1, #]] == DivisorSigma[0, #] &] (* Jean-François Alcover, Mar 18 2013 *)
CROSSREFS
Cf. A069810.
Sequence in context: A171563 A347504 A061657 * A351278 A239457 A235258
KEYWORD
nonn,easy
AUTHOR
Jayanta Basu, Mar 17 2013
STATUS
approved