cp's OEIS Frontend

A358222 Composite numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

%I A358222 #8 Nov 26 2022 08:58:35
%S A358222 6,9,21,25,26,33,38,46,49,65,77,94,141,146,161,185,201,206,207,209,
%T A358222 221,305,321,326,333,341,346,375,377,406,413,453,458,531,581,589,605,
%U A358222 615,689,717,741,745,746,766,819,869,893,965,989,1041,1046,1073,1189,1241,1254,1331,1337,1349,1461,1466,1469,1529,1541,1641
%N A358222 Composite numbers k such that A003415(k) divides A276086(k), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.
%H A358222 Antti Karttunen, <a href="/A358222/b358222.txt">Table of n, a(n) for n = 1..10000</a>
%H A358222 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%o A358222 (PARI)
%o A358222 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
%o A358222 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A358222 A358220(n) = if(n<2,0,!(A276086(n)%A003415(n)));
%o A358222 isA358222(n) = (!isprime(n)&&A358220(n));
%Y A358222 Composite terms in A358221.
%Y A358222 Cf. A003415, A276086, A358220.
%K A358222 nonn
%O A358222 1,1
%A A358222 _Antti Karttunen_, Nov 23 2022