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 A359425 #12 May 14 2025 09:08:56 %S A359425 0,2,2,11,2,19,2,45,18,35,2,85,2,31,40,151,2,125,2,195,36,119,2,313, %T A359425 38,83,120,215,2,418,2,649,124,491,52,628,2,295,88,1057,2,1046,2,1629, %U A359425 414,2303,2,1777,38,1541,496,2241,2,4424,140,6421,300,11315,2,2048,2,83,1002,2013,104,1864,2,2073 %N A359425 Dirichlet convolution of the arithmetic derivative with the primorial base exp-function. %H A359425 Antti Karttunen, <a href="/A359425/b359425.txt">Table of n, a(n) for n = 1..2309</a> %H A359425 <a href="/index/Pri#primorialbase">Index entries for sequences related to primorial base</a> %F A359425 a(n) = Sum_{d|n} A003415(n/d) * A276086(d). %F A359425 a(n) = Sum_{d|n} A347130(n/d) * A383286(d). - _Antti Karttunen_, May 14 2025 %o A359425 (PARI) %o A359425 A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1])); %o A359425 A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); }; %o A359425 A359425(n) = sumdiv(n,d,A003415(n/d)*A276086(d)); %Y A359425 Cf. A003415, A276086, A359425, A347130, A383286. %Y A359425 Cf. also A347389, A347959. %K A359425 nonn,base,look %O A359425 1,2 %A A359425 _Antti Karttunen_, Jan 02 2023