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 A348980 #14 Nov 15 2021 03:40:39
%S A348980 0,1,1,5,1,9,1,17,8,13,1,37,1,17,15,49,1,51,1,57,19,25,1,117,14,29,43,
%T A348980 77,1,105,1,129,27,37,23,191,1,41,31,185,1,141,1,117,99,49,1,325,20,
%U A348980 117,39,137,1,237,31,253,43,61,1,405,1,65,131,321,35,213,1,177,51,209,1,579,1,77,145,197,35,249,1,521
%N A348980 a(n) = Sum_{d|n} d * A322582(n/d), where A322582(n) = n - A003958(n), and A003958 is fully multiplicative with a(p) = (p-1).
%C A348980 Dirichlet convolution of A322582 with the identity function, A000027.
%H A348980 Antti Karttunen, <a href="/A348980/b348980.txt">Table of n, a(n) for n = 1..16384</a>
%F A348980 a(n) = Sum_{d|n} d * A322582(n/d).
%F A348980 For all n >= 1, a(n) <= A347130(n) <= A349140(n).
%F A348980 a(n) = A038040(n) - A349130(n). - _Antti Karttunen_, Nov 14 2021
%t A348980 f[p_, e_] := (p - 1)^e; s[1] = 1; s[n_] := Times @@ f @@@ FactorInteger[n]; a[n_] := DivisorSum[n, #*(n/# - s[n/#]) &]; Array[a, 100] (* _Amiram Eldar_, Nov 08 2021 *)
%o A348980 (PARI)
%o A348980 A003958(n) = { my(f = factor(n)); for(i=1, #f~, f[i, 1]--); factorback(f); };
%o A348980 A322582(n) = (n-A003958(n));
%o A348980 A348980(n) = sumdiv(n,d,d*A322582(n/d));
%Y A348980 Cf. A000027, A003958, A038040, A322582, A348981 (Möbius transform), A348982, A348983, A349130.
%Y A348980 Cf. also A347130, A349140.
%K A348980 nonn
%O A348980 1,4
%A A348980 _Antti Karttunen_, Nov 08 2021