1,2

Table of n, a(n) for n=1..74.

sum(k=1, n, a(k)) is asymptotic to c*n^2 with c=0.3938......

(PARI) a(n)=if(n<1, 0, max(core(n), eulerphi(n)))

Sequence in context: A066069 A019530 A019554 * A254503 A186646 A309108

Adjacent sequences: A076682 A076683 A076684 * A076686 A076687 A076688

nonn

Benoit Cloitre, Oct 25 2002

approved