%I #2 Mar 30 2012 17:34:19
%S 0,2,4,8,6,12,8,16,24,8,30,20,12,24,36,36,14,42,32,16,48,32,54,72,36,
%T 18,36,18,40,140,44,66,22,110,22,66,72,48,72,72,26,130,28,56,28,168,
%U 180,60,30,60,90,30,160,96,96,96,32,96,68,34,180,252,72,36,72,252,114,190,38
%N pi(n)[prime(n+1)-prime(n)], where pi(n) is the number of prime numbers less than or equal to n and prime(k) is the k-th prime.
%e a(2)=pi(2)[prime(3)-prime(2)]=1*(5-3)=2.
%p with(numtheory): a:=n->pi(n)*(ithprime(n+1)-ithprime(n)): seq(a(n),n=1..70);
%t a = Table[(Prime[n + 1] - Prime[n])*PrimePi[n], {n, 1, 200}]
%K nonn
%O 1,2
%A _Roger L. Bagula_, Jun 27 2005