cp's OEIS Frontend

A369958 Numbers k such that A003415(k)/gcd(k, A003415(k)) >= A276086(k)/gcd(k, A276086(k)), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.

%I A369958 #10 Feb 07 2024 20:27:46
%S A369958 6,30,33,42,63,210,212,213,214,220,420,429,462,2310,2312,2313,2314,
%T A369958 2315,2316,2317,2318,2319,2320,2325,2330,2340,2342,2343,2344,2345,
%U A369958 2346,2355,2370,2373,2379,2380,2520,2522,2526,2530,2535,2552,2730,3003,4620,4622,4623,4626,4628,4630,4654,4680,4830,4836,4862,6930,6942,7150
%N A369958 Numbers k such that A003415(k)/gcd(k, A003415(k)) >= A276086(k)/gcd(k, A276086(k)), where A003415 is the arithmetic derivative, and A276086 is the primorial base exp-function.
%H A369958 Antti Karttunen, <a href="/A369958/b369958.txt">Table of n, a(n) for n = 1..13305  (terms up to 3*A002110(9))</a>
%F A369958 {k | A083345(k) >= A351251(k)}.
%o A369958 (PARI)
%o A369958 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
%o A369958 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A369958 isA369958(n) = ((A003415(n)/gcd(n, A003415(n))) >= (A276086(n)/gcd(n, A276086(n))));
%Y A369958 Cf. A003415, A083345, A276086, A351251.
%Y A369958 Subsequences: A002110 (after its two initial terms), A369959, A369960.
%Y A369958 Cf. also A351228.
%K A369958 nonn
%O A369958 1,1
%A A369958 _Antti Karttunen_, Feb 07 2024