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 A349385 #13 Nov 26 2021 16:17:51 %S A349385 1,-1,-2,-1,-3,4,-5,-1,-2,6,-6,4,-8,10,12,-1,-9,4,-11,6,20,12,-14,4, %T A349385 -3,16,-2,10,-15,-24,-18,-1,24,18,30,4,-20,22,32,6,-21,-40,-23,12,12, %U A349385 28,-26,4,-5,6,36,16,-29,4,36,10,44,30,-30,-24,-33,36,20,-1,48,-48,-35,18,56,-60,-36,4,-39,40,12,22,60 %N A349385 Dirichlet convolution of A048673 with the Dirichlet inverse of A003961, where A003961 is fully multiplicative with a(p) = nextprime(p), and A048673(n) = (1+A003961(n))/2. %C A349385 Convolving this with A003973 gives A336840. %H A349385 Antti Karttunen, <a href="/A349385/b349385.txt">Table of n, a(n) for n = 1..20000</a> %H A349385 <a href="/index/Pri#prime_indices">Index entries for sequences computed from indices in prime factorization</a> %F A349385 a(n) = Sum_{d|n} A048673(n/d) * A346234(d). %F A349385 a(n) = A349386(n) - A349384(n). %o A349385 (PARI) %o A349385 A003961(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; %o A349385 A048673(n) = (A003961(n)+1)/2; %o A349385 A346234(n) = (moebius(n)*A003961(n)); %o A349385 A349385(n) = sumdiv(n,d,A048673(n/d)*A346234(d)); %Y A349385 Cf. A003961, A048673, A346234, A349384 (Dirichlet inverse), A349386 (sum with it). %Y A349385 Cf. also A003973, A336840. %K A349385 sign %O A349385 1,3 %A A349385 _Antti Karttunen_, Nov 17 2021