A374123 - OEIS

%I #6 Jun 30 2024 09:15:33

%S 0,0,1,2,4,6,7,30,12,12,17,210,20,150,67,28,32,150,33,30,44,104,71,

%T 210,52,60,313,54,148,150,71,30,80,292,317,192,84,210,79,116,108,210,

%U 229,330,164,114,83,150,128,60,145,124,292,210,135,36,324,128,329,330,172,30,91,354,192,108,257,30,308,316,59,210

%N a(n) = A328768(n) mod 360, where A328768 is the first primorial based variant of the arithmetic derivative.

%H Antti Karttunen, <a href="/A374123/b374123.txt">Table of n, a(n) for n = 0..16384</a>

%o (PARI)

%o A002110(n) = prod(i=1,n,prime(i));

%o A328768(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]*A002110(primepi(f[i,1])-1)/f[i, 1]));

%o A374123(n) = (A328768(n)%360);

%Y Cf. A002110, A328768.

%Y Cf. A042965 (indices of even terms), A016825 (of odd terms), A152822 (antiparity of terms), A373992 (indices of multiples of 3).

%Y Cf. also A372576, A374124, A374125.

%K nonn

%O 0,4

%A _Antti Karttunen_, Jun 30 2024