1,3

Table of n, a(n) for n=1..80.

sum(k=1, n, a(k)) is asymptotic to c*n^2 with c=0.239......

(PARI) a(n)=min(core(n), eulerphi(n))

Sequence in context: A232626 A322250 A175542 * A114810 A300718 A093819

Adjacent sequences: A076683 A076684 A076685 * A076687 A076688 A076689

nonn

Benoit Cloitre, Oct 25 2002

approved