A146323 - OEIS

%I #4 Dec 19 2015 09:32:56

%S 1,2,2,3,3,3,3,4,4,4,4,4,5,5,5,5,5,5,5,5,5,6,6,6,6,6,6,6,6,6,6,6,6,6,

%T 6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8,8,8,8,8,8,

%U 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,9

%N a(n)= integer part [ Sum_i=1..n (1/phi(i))]

%C Looking on the number of 1`s, 2`s,...k`s in this sequence we obtain the sequence (1,2,4,5,9,16,25,42,72,...). Lim_k-->oo [number of (k+1)`s / number of(k`s)] = sqrt(e).

%t IntegerPart[Accumulate[1/EulerPhi[Range[110]]]] (* _Harvey P. Dale_, Dec 19 2015 *)

%Y Cf. A000010

%K nonn

%O 1,2

%A _Ctibor O. Zizka_, Oct 30 2008