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 A328382 #19 Nov 26 2022 08:58:15 %S A328382 0,0,1,0,0,0,3,0,3,0,9,0,3,6,1,0,20,0,15,0,7,0,9,0,0,24,25,0,7,0,21,0, %T A328382 6,6,35,0,0,2,43,0,11,0,45,36,0,0,91,0,15,10,35,0,1,14,61,4,5,0,49,0, %U A328382 15,39,57,0,1,0,15,14,22,0,133,0,9,35,65,0,19,0,71,30,42,0,121,2,30,6,105,0,97,6,69,18,0,6,83,0,63,15,35,0,21 %N A328382 a(n) = A276086(n) mod A003415(n), where A276086 is the primorial base exp-function and A003415 is the arithmetic derivative. %H A328382 Antti Karttunen, <a href="/A328382/b328382.txt">Table of n, a(n) for n = 2..30030</a> %H A328382 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a> %F A328382 a(n) = A276086(n) mod A003415(n). %F A328382 For n >= 2, gcd(a(n), A003415(n)) = A327858(n). %o A328382 (PARI) %o A328382 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1])); %o A328382 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); }; %o A328382 A328382(n) = (A276086(n)%A003415(n)); %Y A328382 Cf. A003415, A276086, A327858, A358220, A358221 (positions of 0's), A358232 (of 1's), A358228 (of odd terms), A358229 (of even terms), A358227 (parity of terms). %Y A328382 Cf. also A328386. %K A328382 nonn %O A328382 2,7 %A A328382 _Antti Karttunen_, Oct 15 2019