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A112381 Zero-free semiprimes. 1
4, 6, 9, 14, 15, 21, 22, 25, 26, 33, 34, 35, 38, 39, 46, 49, 51, 55, 57, 58, 62, 65, 69, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 111, 115, 118, 119, 121, 122, 123, 129, 133, 134, 141, 142, 143, 145, 146, 155, 158, 159, 161, 166, 169, 177, 178, 183, 185, 187 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Intersection of A001358 and A052382. - Michel Marcus, Oct 09 2013
LINKS
EXAMPLE
74 is in the sequence because it is a semiprime (2*37) and does not have 0 in digits. - Michel Marcus, Oct 14 2013
MATHEMATICA
SemiPrimeQ[n_Integer] := If[Abs[n] < 2, False, (2 == Plus @@ Transpose[FactorInteger[Abs[n]]][[2]])]; Select[Range[2, 200], SemiPrimeQ[#] && Min[IntegerDigits[#]] > 0 &] (* T. D. Noe, Oct 11 2013 *)
PROG
(PARI) lista(nn) = {vec = vector(nn, i, i); pp = select(i->(((bigomega(i) == 2) && vecmin(digits(i)))), vec); print(pp); } \\ Michel Marcus, Oct 09 2013
CROSSREFS
Sequence in context: A241451 A354965 A288379 * A182150 A108634 A135355
KEYWORD
base,nonn
AUTHOR
Zak Seidov, May 30 2006
EXTENSIONS
Data corrected by Michel Marcus, Oct 14 2013
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)