cp's OEIS Frontend

A228423 Sum of the squared primes less than or equal to n.

%I A228423 #15 Aug 20 2023 10:50:55
%S A228423 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 A228423 38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,38,
%U A228423 87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87,87
%N A228423 Sum of the squared primes less than or equal to n.
%F A228423 a(n) = Sum_{ i <= n | Omega(i) = 2} i * (1 - mu(i)).
%F A228423 a(n) = A081738(A000196(n)). - _Michel Marcus_, Aug 20 2023
%e A228423 a(10) = 13; 4 and 9 are the only squared primes less than or equal to 10 and their sum is 13.
%p A228423 with(numtheory); a:=n->add('if'(bigomega(i)=2, i*(1-mobius(i)), 0), i=1..n); seq(a(n), n=1..100);
%t A228423 With[{sp=Prime[Range[10]]^2},Table[Total[Select[sp,#<=n&]],{n,100}]] (* _Harvey P. Dale_, Nov 11 2016 *)
%Y A228423 Cf. A024450.
%Y A228423 Cf. A081738, A000196.
%K A228423 nonn
%O A228423 1,4
%A A228423 _Wesley Ivan Hurt_, Nov 09 2013