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Numbers n such that sigma(n) = phi(n) + phi(n-1) + phi(n-2).
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%I #8 Feb 11 2014 19:05:25

%S 3,82,1898,2457,4294,4526,4748,8494,14798,15566,16095,34988,97402,

%T 883082,1015658,1121686,2699445,3090945,3714454,5668598,10376835,

%U 13032398,32290154,40250422,123960795,150301604,157673985,165102854,167691466,235444618,289453814

%N Numbers n such that sigma(n) = phi(n) + phi(n-1) + phi(n-2).

%e sigma(82) = 126 = 40 + 54 + 32 = phi(82) + phi(82-1) + phi(82-2), so 82 is a term of the sequence.

%t Select[Range[3, 10^5], EulerPhi[ # ] + EulerPhi[ # - 1] + EulerPhi[ # - 2] == DivisorSigma[1, # ] &]

%K nonn

%O 1,1

%A _Joseph L. Pe_, Feb 19 2002

%E a(14)-a(28) from _Donovan Johnson_, Feb 05 2010

%E a(29)-a(31) from _Donovan Johnson_, Feb 08 2012