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1,2
Harvey P. Dale, Table of n, a(n) for n = 1..1000
205+phi(205)+sigma(205) = 617 (prime).
Select[Range[500], PrimeQ[#+EulerPhi[#]+DivisorSigma[1, #]]&] (* Harvey P. Dale, Nov 09 2014 *)
Cf. A078762, A068080.
Sequence in context: A188075 A121914 A110341 * A256715 A022265 A120389
Adjacent sequences: A116032 A116033 A116034 * A116036 A116037 A116038
nonn
Giovanni Resta, Feb 13 2006
approved