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 A349570 #14 Jan 09 2024 13:19:42 %S A349570 1,0,1,4,11,24,57,112,244,480,1013,1972,4083,8064,16331,32512,65519, %T A349570 130488,262125,523244,1048377,2095104,4194281,8384176,16777136, %U A349570 33546240,67108096,134201316,268435427,536836584,1073741793,2147418112,4294964213,8589803520,17179868787,34359470272,68719476699,137438429184,274877894643 %N A349570 Dirichlet convolution of A011782 [2^(n-1)] with A055615 (Dirichlet inverse of n). %C A349570 Dirichlet convolution of this sequence with phi (A000010) is A000740, with sigma (A000203) it is A034729, and with A018804 it is A034738. %H A349570 Antti Karttunen, <a href="/A349570/b349570.txt">Table of n, a(n) for n = 1..1001</a> %F A349570 a(n) = Sum_{d|n} 2^(d-1) * A055615(n/d). %t A349570 a[n_] := DivisorSum[n, # * MoebiusMu[#] * 2^(n/# - 1) &]; Array[a, 40] (* _Amiram Eldar_, Nov 22 2021 *) %o A349570 (PARI) %o A349570 A055615(n) = (n*moebius(n)); %o A349570 A349570(n) = sumdiv(n,d,(2^(d-1)) * A055615(n/d)); %Y A349570 Cf. A011782, A055615, A349569 (Dirichlet inverse). %Y A349570 Cf. also A000010, A000740, A000203, A018804, A034729, A034738, A349564, A349566, A349568. %K A349570 nonn %O A349570 1,4 %A A349570 _Antti Karttunen_, Nov 22 2021