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A085802
Numbers whose sum of digits is a semiprime.
1
4, 6, 9, 13, 15, 18, 19, 22, 24, 27, 28, 31, 33, 36, 37, 40, 42, 45, 46, 51, 54, 55, 59, 60, 63, 64, 68, 69, 72, 73, 77, 78, 81, 82, 86, 87, 90, 91, 95, 96, 103, 105, 108, 109, 112, 114, 117, 118, 121, 123, 126, 127, 130, 132, 135, 136, 141, 144, 145, 149, 150, 153
OFFSET
1,1
MATHEMATICA
Select[Range[200], PrimeOmega[Total[IntegerDigits[#]]]==2&] (* Harvey P. Dale, Sep 15 2023 *)
PROG
(PARI) isok(k)=bigomega(sumdigits(k))==2 \\ Andrew Howroyd, Sep 18 2024
CROSSREFS
Cf. A001358.
Sequence in context: A020165 A368196 A110607 * A084916 A187910 A283623
KEYWORD
base,easy,nonn
AUTHOR
Jason Earls, Jul 24 2003
EXTENSIONS
Offset changed by Andrew Howroyd, Sep 18 2024
STATUS
approved