cp's OEIS Frontend

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.

A349432 Dirichlet convolution of A000027 (the identity function) with A349134 (Dirichlet inverse of Kimberling's paraphrases).

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%I A349432 #10 Nov 21 2021 01:18:31
%S A349432 1,1,1,2,2,1,3,4,2,2,5,2,6,3,0,8,8,2,9,4,0,5,11,4,6,6,4,6,14,0,15,16,
%T A349432 0,8,0,4,18,9,0,8,20,0,21,10,-2,11,23,8,12,6,0,12,26,4,0,12,0,14,29,0,
%U A349432 30,15,-3,32,0,0,33,16,0,0,35,8,36,18,-4,18,0,0,39,16,8,20,41,0,0,21,0,20,44,-2,0,22,0,23
%N A349432 Dirichlet convolution of A000027 (the identity function) with A349134 (Dirichlet inverse of Kimberling's paraphrases).
%H A349432 Antti Karttunen, <a href="/A349432/b349432.txt">Table of n, a(n) for n = 1..20000</a>
%t A349432 k[n_] := (n / 2^IntegerExponent[n, 2] + 1)/2; kinv[1] = 1; kinv[n_] := kinv[n] = -DivisorSum[n, kinv[#] * k[n/#] &, # < n &]; a[n_] := DivisorSum[n, # * kinv[n/#] &]; Array[a, 100] (* _Amiram Eldar_, Nov 18 2021 *)
%o A349432 (PARI)
%o A349432 up_to = 16384;
%o A349432 DirInverseCorrect(v) = { my(u=vector(#v)); u[1] = (1/v[1]); for(n=2, #v, u[n] = (-u[1]*sumdiv(n, d, if(d<n, v[n/d]*u[d], 0)))); (u) }; \\ Compute the Dirichlet inverse of the sequence given in input vector v.
%o A349432 A003602(n) = (1+(n>>valuation(n,2)))/2;
%o A349432 v349134 = DirInverseCorrect(vector(up_to,n,A003602(n)));
%o A349432 A349134(n) = v349134[n];
%o A349432 A003602(n) = (1+(n>>valuation(n,2)))/2;
%o A349432 A055615(n) = (n*moebius(n));
%o A349432 A349432(n) = sumdiv(n,d,d*A349134(n/d));
%Y A349432 Cf. A003602, A055615, A349134, A349431 (Dirichlet inverse), A349433 (sum with it).
%Y A349432 Cf. also A349445, A349448.
%K A349432 sign
%O A349432 1,4
%A A349432 _Antti Karttunen_, Nov 17 2021