A230095 Odious numbers (A000069) that are the product of exactly two distinct primes.

14, 21, 22, 26, 35, 38, 55, 62, 69, 74, 82, 87, 91, 93, 94, 115, 118, 122, 133, 134, 143, 145, 146, 155, 158, 161, 185, 194, 203, 205, 206, 213, 214, 217, 218, 247, 253, 254, 259, 262, 265, 274, 295, 299, 301, 302, 309, 314, 319, 321, 327, 334, 339, 341, 346

Offset

1,1

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

E. Fouvry, C. Mauduit, Sommes des chiffres et nombres presque premiers, (French) [Sums of digits and almost primes] Math. Ann. 305 (1996), no. 3, 571--599. MR1397437 (97k:11029).

Mathematica

Select[Range[400], OddQ[DigitCount[#, 2, 1]]&&PrimeNu[#]==PrimeOmega[#]==2&] (* Harvey P. Dale, May 21 2024 *)

Prog

(PARI) isodious(n)=b = binary(n); sum(i=1, #b, b[i]==1) % 2;
isok(n) = isodious(n) && (bigomega(n)==2) && (omega(n)==2); \\ Michel Marcus, Oct 12 2013
(PARI) list(lim)=my(v=List()); forprime(p=2, lim\2, forprime(q=2, min(lim\p, p-1), if(hammingweight(p*q)%2, listput(v, p*q)))); Set(v) \\ Charles R Greathouse IV, Jan 31 2017

Crossrefs

Cf. A000069, A027697, A130593.

Sequence in context: A167170 A213536 A330137 * A133185 A013629 A234802

Adjacent sequences: A230092 A230093 A230094 * A230096 A230097 A230098

Keyword

nonn,base

Author

N. J. A. Sloane, Oct 11 2013

Extensions

More terms from Michel Marcus, Oct 12 2013

Status

approved