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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).
Table of n, a(n) for n=1..105.
IntegerPart[Accumulate[1/EulerPhi[Range]]] (* Harvey P. Dale, Dec 19 2015 *)
Sequence in context: A156079 A268708 A061555 * A071626 A182008 A106457
Adjacent sequences: A146320 A146321 A146322 * A146324 A146325 A146326
Ctibor O. Zizka, Oct 30 2008