A217736 Sum of first n squares of semiprimes.

16, 52, 133, 233, 429, 654, 1095, 1579, 2204, 2880, 3969, 5125, 6350, 7794, 9315, 11431, 13832, 16433, 19458, 22707, 26071, 29915, 34140, 38901, 44377, 50306, 57030, 64255, 71651, 79220, 87501, 96150, 104986, 114011, 125247, 137568, 150793, 164717, 178878

Offset: 1

Author

Kevin L. Schwartz and Christian N. K. Anderson, Mar 22 2013

Keywords

• nonn

Comments

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

Examples

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

Links

• Christian N. K. Anderson, Table of n, a(n) for n = 1..10000

Crossrefs

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

Programs

Mathematica

Accumulate[Select[Range[200],PrimeOmega[#]==2&]^2] (* Harvey P. Dale, Mar 13 2018 *)