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%I #9 Jun 16 2016 23:27:54
%S 7,22,31,37,52,67,82,94,97,112,115,127,136,142,148,157,172,178,187,
%T 199,202,214,217,220,232,241,247,262,277,283,292,304,307,322,325,337,
%U 346,352,367,382,388,397,409,412,427,430,442,445,451,457,472,487,502,517,532,535,547,562,577,592,598,607,622,637,643,652,661,667,682,697,712,724,727,742,757,772,787,802,808,817
%N Numbers such that (2n+1) + phi(2n+1) <= sigma(2n+1)
%C It appears that the equation x + phi(x) = sigma(x) has the unique solution x=2. It is easy to show that this is the only even solution to the equation, but for odd solutions this is less obvious. The present sequence is motivated by the observation that for most odd numbers, the l.h.s. is larger than the r.h.s. (while the opposite is the case for all even numbers). (See also formulas in A228947.)
%o (PARI) select(n->(2*n+1+eulerphi(2*n+1)<sigma(2*n+1)),vector(900,n,n-1))
%Y Cf. A228947, A051612 and references there, A000203, A000010.
%K nonn
%O 1,1
%A _M. F. Hasler_, Oct 05 2013
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