%I #15 Feb 18 2019 08:54:56

%S 1,2,4,5,9,10,14,15,18,23,25,30,34,35,38,43,49,50,56,59,60,65,69,74,

%T 81,84,85,88,90,93,107,110,115,116,125,126,132,137,140,145,151,152,

%U 162,163,166,167,179,190,193,194,197,202,204,213,218,223,228,229,235,238,240

%N a(n) = pi(n) plus the number of nonprimes less than prime(n).

%C The number of primes less than n plus the number of nonprimes less than the n-th prime.

%H G. C. Greubel, <a href="/A167180/b167180.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A000720(n) + A014689(n).

%p A000720 := proc(n) numtheory[pi](n) ; end proc:

%p A014689 := proc(n) ithprime(n) -n ; end proc:

%p A167180 := proc(n) A000720(n)+A014689(n) ; end proc: seq(A167180(n),n=1..120) ; # _R. J. Mathar_, May 21 2010

%t Table[PrimePi[n] + Prime[n] - n , {n, 1, 20}] (* _G. C. Greubel_, Jun 04 2016 *)

%Y Cf. A000720, A014689.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Oct 29 2009

%E Corrected (89 replaced with 88, 94 with 93, 127 with 126, 146 with 145, etc.) by _R. J. Mathar_, May 21 2010