A085802 Numbers whose sum of digits is a semiprime.

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

Links

Table of n, a(n) for n=1..62.

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

Adjacent sequences: A085799 A085800 A085801 * A085803 A085804 A085805

Keyword

base,easy,nonn

Author

Jason Earls, Jul 24 2003

Extensions

Offset changed by Andrew Howroyd, Sep 18 2024

Status

approved