A073162 - OEIS

%I #21 Oct 05 2020 17:53:15

%S 1,3,17,37,9107,156335,679083,1068131,4883039,101691357

%N n is such that partial sum of pi(k) from 1 to n is divisible by n.

%C a(11) > 10^12. - _Donovan Johnson_, Mar 19 2011

%C a(11) > 10^13. - _Lucas A. Brown_, Oct 05 2020

%F Solutions to Mod[A046992(x), x]=0

%e a(3) = 17 because 0+1+2+2+3+3+4+4+4+4+5+5+6+6+6+6+7 = 68 = 4*17.

%t s = 0; Do[s = s + PrimePi[n]; If[ IntegerQ[s/n], Print[{n, s, s/n}]], {n, 1, 10^8}]

%Y Cf. A046992, A000720, A073163, A073164, A073224.

%K nonn,more

%O 1,2

%A _Labos Elemer_, Jul 18 2002

%E Edited and extended by _Robert G. Wilson v_, Jul 20 2002

%E a(10) from _Donovan Johnson_, Dec 15 2009