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1,2

Table of n, a(n) for n=1..69.

a(n) = ( A018804(n) + A000188(n) ) / 2 [Max Alekseyev, Sep 05 2010]

(PARI) a(n)={ my(ct=0); for(i=0, n-1, for(j=0, i, ct+=(Mod(i*j, n)==0) ) ); ct; } \\ Joerg Arndt, Aug 03 2013

Sequence in context: A063914 A209187 A166250 * A208323 A067284 A123339

Adjacent sequences: A174085 A174086 A174087 * A174089 A174090 A174091

nonn

Russell Easterly, Mar 06 2010

More terms from Max Alekseyev, Sep 05 2010

Better name from Joerg Arndt, Aug 03 2013

approved