|
%I #11 Dec 21 2023 10:22:35
%S 1,6,8,12,14,16,18,20,22,24,28,32,36,38,40,44,46,48,52,54,56,60,62,64,
%T 68,72,76,80,84,86,88,92,94,96,98,100,104,108,112,116,118,120,124,128,
%U 132,134,136,140,142,144,148,152,156,158,160,162,164,166,168,172,176,180,184,188,192,196,200,204,206,208,212
%N Numbers k such that the cototient of k (= k-phi(k)) is a multiple of 4.
%C Union of {1}, A008586 \ {0, 4} and A196445 \ {2}. - _Amiram Eldar_, Dec 21 2023
%t Select[Range[200], Divisible[# - EulerPhi[#], 4] &] (* _Amiram Eldar_, May 17 2022 *)
%o (PARI)
%o A354097(n) = (0==((n-eulerphi(n))%4));
%o isA354098(n) = A354097(n);
%Y Cf. A000010, A010873, A051953, A354097 (characteristic function).
%Y Cf. also A292763, A354038.
%Y Cf. A008586, A196445.
%K nonn
%O 1,2
%A _Antti Karttunen_, May 17 2022
|
