%I #18 Mar 13 2018 11:58:31

%S 16,52,133,233,429,654,1095,1579,2204,2880,3969,5125,6350,7794,9315,

%T 11431,13832,16433,19458,22707,26071,29915,34140,38901,44377,50306,

%U 57030,64255,71651,79220,87501,96150,104986,114011,125247,137568,150793,164717,178878

%N Sum of first n squares of semiprimes.

%C There are 68 such numbers less than one million; a(68) = 988849.

%H Christian N. K. Anderson, <a href="/A217736/b217736.txt">Table of n, a(n) for n = 1..10000</a>

%e a(3) = 4^2 + 6^2 + 9^2 = 133.

%t Accumulate[Select[Range[200],PrimeOmega[#]==2&]^2] (* _Harvey P. Dale_, Mar 13 2018 *)

%Y Cf. A062198. Equals sum(A001358^2), and sum(A074985).

%K nonn

%O 1,1

%A _Kevin L. Schwartz_ and _Christian N. K. Anderson_, Mar 22 2013