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Numbers k whose arithmetic derivative, A003415(k), has the opposite parity to k.
4

%I #8 Jan 14 2023 17:19:20

%S 1,2,6,9,10,14,15,18,21,22,25,26,30,33,34,35,38,39,42,46,49,50,51,54,

%T 55,57,58,62,65,66,69,70,74,77,78,81,82,85,86,87,90,91,93,94,95,98,

%U 102,106,110,111,114,115,118,119,121,122,123,126,129,130,133,134,135,138,141,142,143,145,146,150,154

%N Numbers k whose arithmetic derivative, A003415(k), has the opposite parity to k.

%o (PARI) isA359821(n) = A359820(n);

%Y Cf. A003415, A359820 (characteristic function), A359822 (complement).

%Y Positions of odd terms in A129283 and in A168036.

%K nonn,easy

%O 1,2

%A _Antti Karttunen_, Jan 14 2023

%E Name edited by _Peter Munn_, Jan 14 2023