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Sum of the squared primes less than or equal to n.
0

%I #15 Aug 20 2023 10:50:55

%S 0,0,0,4,4,4,4,4,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,13,38,

%T 38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,

%U 87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87

%N Sum of the squared primes less than or equal to n.

%F a(n) = Sum_{ i <= n | Omega(i) = 2} i * (1 - mu(i)).

%F a(n) = A081738(A000196(n)). - _Michel Marcus_, Aug 20 2023

%e a(10) = 13; 4 and 9 are the only squared primes less than or equal to 10 and their sum is 13.

%p with(numtheory); a:=n->add('if'(bigomega(i)=2, i*(1-mobius(i)), 0), i=1..n); seq(a(n), n=1..100);

%t With[{sp=Prime[Range[10]]^2},Table[Total[Select[sp,#<=n&]],{n,100}]] (* _Harvey P. Dale_, Nov 11 2016 *)

%Y Cf. A024450.

%Y Cf. A081738, A000196.

%K nonn

%O 1,4

%A _Wesley Ivan Hurt_, Nov 09 2013