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A373494 Numbers k for which A059975(k) and A003415(k) are both multiples of 3, where A059975 is fully additive with a(p) = p-1, and A003415 is the arithmetic derivative. 6

%I #7 Jun 10 2024 17:45:25

%S 1,8,20,27,36,44,50,64,68,90,92,110,116,125,160,162,164,170,188,189,

%T 198,212,216,225,230,236,242,252,275,284,288,290,306,332,343,351,352,

%U 356,374,400,404,405,410,414,425,428,452,468,470,495,506,512,513,522,524,530,540,544,548,575,578,590,596,605,630,637

%N Numbers k for which A059975(k) and A003415(k) are both multiples of 3, where A059975 is fully additive with a(p) = p-1, and A003415 is the arithmetic derivative.

%C A multiplicative semigroup: if m and n are in the sequence, then so is m*n.

%H Antti Karttunen, <a href="/A373494/b373494.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI) isA373494 = A373493;

%Y Cf. A003415, A059975, A373492 (subsequence), A373493 (characteristic function).

%Y Positions of multiples of 3 in A373378.

%Y Intersection of A373385 and A327863.

%K nonn

%O 1,2

%A _Antti Karttunen_, Jun 10 2024

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Last modified September 13 11:59 EDT 2024. Contains 375907 sequences. (Running on oeis4.)