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A217736
Sum of first n squares of semiprimes.
1
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
1,1
COMMENTS
There are 68 such numbers less than one million; a(68) = 988849.
LINKS
Christian N. K. Anderson, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 4^2 + 6^2 + 9^2 = 133.
MATHEMATICA
Accumulate[Select[Range[200], PrimeOmega[#]==2&]^2] (* Harvey P. Dale, Mar 13 2018 *)
CROSSREFS
Cf. A062198. Equals sum(A001358^2), and sum(A074985).
Sequence in context: A241490 A009931 A009936 * A211578 A211592 A235653
KEYWORD
nonn
STATUS
approved