A064677 - OEIS

%I #12 Jun 21 2018 01:59:19

%S 0,0,0,1,1,5,2,7,3,12,1,19,6,14,12,19,9,26,8,32,18,24,9,43,18,31,27,

%T 45,16,48,17,46,35,33,35,74,20,44,38,72,27,73,28,66,62,46,21,105,40,

%U 74,51,81,28,98,50,98,62,68,39,149,34,64,82,107,62,112,43,97,75,121,46,167

%N a(n) = sigma(n) - D(n) - pi(n), where D(n)=A001223, pi(n)= A000720.

%H Harry J. Smith, <a href="/A064677/b064677.txt">Table of n, a(n) for n = 1..1000</a>

%o (PARI) pi(x, c) = forprime(p=2,x,c++); c d(n) = prime(n+1)-prime(n) for(n=1,200,print1(sigma(n)-d(n)-pi(n)," "))

%o (PARI) { for (n=1, 1000, a=sigma(n) - (prime(n + 1) - prime(n)) - primepi(n); write("b064677.txt", n, " ", a) ) } \\ _Harry J. Smith_, Sep 21 2009

%K easy,nonn

%O 1,6

%A _Jason Earls_, Oct 09 2001