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A341044 Numbers k such that A318996(k) is prime.

%I A341044 #10 Feb 04 2021 05:42:12
%S A341044 8,9,10,14,15,21,22,25,26,33,34,39,42,46,57,62,65,66,69,72,74,76,80,
%T A341044 82,87,91,92,93,94,95,100,106,111,116,119,121,122,129,133,134,145,146,
%U A341044 159,162,166,172,176,177,183,184,190,194,202,203,206,208,213,214,215,219,232,236,237,238,240,243
%N A341044 Numbers k such that A318996(k) is prime.
%C A341044 Contains 2*p for p in A023201 and 3*p for p in A023203.
%H A341044 Robert Israel, <a href="/A341044/b341044.txt">Table of n, a(n) for n = 1..10000</a>
%e A341044 a(3) = 10 is a term because A318996(10) = 11 is prime.
%p A341044 f:= proc(n) local s,D,t;
%p A341044   D:= numtheory:-divisors(n);
%p A341044   s:= convert(D,`+`);
%p A341044   add(s mod t, t=D)
%p A341044 end proc:
%p A341044 select(t -> isprime(f(t)), [$1..1000]);
%o A341044 (PARI) f(n) = my(sn = sigma(n)); sumdiv(n, d, sn % d); \\ A318996
%o A341044 isok(k) = isprime(f(k)); \\ _Michel Marcus_, Feb 04 2021
%Y A341044 Cf. A023201, A023203, A318996.
%K A341044 nonn
%O A341044 1,1
%A A341044 _J. M. Bergot_ and _Robert Israel_, Feb 03 2021