A361967 - OEIS

%I #15 Dec 24 2024 07:30:16

%S 2,2,1,2,0,3,1,4,0,2,0,5,0,1,1,2,0,3,0,2,0,2,0,8,0,2,0,3,0,4,1,4,0,0,

%T 0,6,0,0,0,4,0,3,0,2,0,2,0,11,0,0,0,2,0,1,0,4,0,2,0,8,0,1,1,2,0,3,0,0,

%U 0,3,0,11,0,0,0,0,0,3,0,8,0,2,0,5,0,0,0

%N Number of numbers k such that uphi(k) = n, where uphi is the unitary totient function (A047994).

%H Amiram Eldar, <a href="/A361967/b361967.txt">Table of n, a(n) for n = 1..10000</a>

%F a(A347771(n)) = 0.

%F a(A361969(n)) = 1.

%F a(A361970(n)) = n.

%F Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = A327837. - _Amiram Eldar_, Dec 24 2024

%t a[n_] := Length[invUPhi[n]]; Array[a, 100] (* using the function invUPhi from A361966 *)

%Y Row lengths of A361966.

%Y The unitary version of A014197.

%Y Cf. A047994, A135347, A327837, A347771 (positions of 0's), A361966, A361968 (indices of records), A361969 (positions of 1's), A361970, A361971 (record values).

%K nonn

%O 1,1

%A _Amiram Eldar_, Apr 01 2023