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%I #15 May 21 2022 08:42:13
%S 2,3,5,115,143,287,371,413,623,791,4067,10031,24149,32335,39689,88403,
%T 93443,107365,148735,168833,212993,427763,555947,650095,925253,
%U 1017821,1117457,1139467,1229327,1270801,1407295,2184221,2294509,2913757,3258355,4699981,5747291
%N Numbers k such that phi(k) + phi(k+1) = sigma(k).
%H Amiram Eldar, <a href="/A067799/b067799.txt">Table of n, a(n) for n = 1..138</a>
%t Select[Range[10^6], EulerPhi[#] + EulerPhi[# + 1] == DivisorSigma[1, #] &] (* _Amiram Eldar_, May 21 2022 *)
%Y Cf. A000010, A000203, A092404.
%K nonn
%O 1,1
%A _Benoit Cloitre_, Feb 07 2002
%E More terms from _Dean Hickerson_, Feb 16 2002
%E More terms from _Amiram Eldar_, May 21 2022