cp's OEIS Frontend

A366445 Triangle read by rows: T(n,k) = A023900(n/k)*phi(k) if k divides n, T(n,k) = 0 otherwise (n >= 1, 1 <= k <= n).

%I A366445 #31 Oct 14 2023 14:05:54
%S A366445 1,-1,1,-2,0,2,-1,-1,0,2,-4,0,0,0,4,2,-2,-2,0,0,2,-6,0,0,0,0,0,6,-1,
%T A366445 -1,0,-2,0,0,0,4,-2,0,-4,0,0,0,0,0,6,4,-4,0,0,-4,0,0,0,0,4,-10,0,0,0,
%U A366445 0,0,0,0,0,0,10,2,2,-2,-4,0,-2,0,0,0,0,0,4
%N A366445 Triangle read by rows: T(n,k) = A023900(n/k)*phi(k) if k divides n, T(n,k) = 0 otherwise (n >= 1, 1 <= k <= n).
%C A366445 Sum_{k=1..n} T(n,k) = A063524(n).
%F A366445 T(n,k) = A023900(n/k)*phi(k) if k divides n, T(n,k) = 0 otherwise (n >= 1, 1 <= k <= n).
%e A366445 {
%e A366445 {1}, = 1
%e A366445 {-1, 1}, = 0
%e A366445 {-2, 0, 2}, = 0
%e A366445 {-1, -1, 0, 2}, = 0
%e A366445 {-4, 0, 0, 0, 4}, = 0
%e A366445 {2, -2, -2, 0, 0, 2}, = 0
%e A366445 {-6, 0, 0, 0, 0, 0, 6}, = 0
%e A366445 {-1, -1, 0, -2, 0, 0, 0, 4}, = 0
%e A366445 {-2, 0, -4, 0, 0, 0, 0, 0, 6}, = 0
%e A366445 {4, -4, 0, 0, -4, 0, 0, 0, 0, 4}, = 0
%e A366445 {-10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10}, = 0
%e A366445 {2, 2, -2, -4, 0, -2, 0, 0, 0, 0, 0, 4} = 0
%e A366445 }
%t A366445 nn = 12; g[n_] := DivisorSum[n, MoebiusMu[#] # &]; Flatten[Table[Table[If[Mod[n, k] == 0, g[n/k]*EulerPhi[k], 0], {k, 1, n}], {n, 1, nn}]]
%Y A366445 Cf. A000010, A023900, A366444, A054524, A054525, A063524, A054522, A054523, A129691, A127649.
%K A366445 sign,tabl
%O A366445 1,4
%A A366445 _Mats Granvik_, Oct 12 2023