This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A373849 #9 Jun 23 2024 21:42:50
%S A373849 1,2,2,5,5,17,0,9,3,24,38,89,9,49,66,142,193,449,104,249,351,740,1112,
%T A373849 2249,581,1240,1860,3723,5593,11249,-24,13,-59,28,44,114,-25,69,84,
%U A373849 194,247,629,134,349,477,1011,1550,3149,763,1736,2580,5230,7819,15749,4294,8734,13033,26228,39344,78749,-43,97,114,243
%N A373849 Difference between the primorial base exp-function and the arithmetic derivative.
%H A373849 Antti Karttunen, <a href="/A373849/b373849.txt">Table of n, a(n) for n = 0..30030</a>
%H A373849 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a>
%F A373849 a(n) = A276086(n) - A003415(n).
%o A373849 (PARI)
%o A373849 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
%o A373849 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
%o A373849 A373849(n) = (A276086(n)-A003415(n));
%Y A373849 Cf. A003415, A276086, A327858 [= gcd(a(n), A003415(n))], A351228 (indices of nonpositive terms).
%Y A373849 Cf. A328382, A369971, A373603.
%Y A373849 Cf. A359821 (positions of even terms), A359822 (of odd terms).
%K A373849 sign
%O A373849 0,2
%A A373849 _Antti Karttunen_, Jun 23 2024