A108634 Semiprimes with ordered digits.

4, 6, 9, 14, 15, 22, 25, 26, 33, 34, 35, 38, 39, 46, 49, 55, 57, 58, 69, 77, 111, 115, 118, 119, 122, 123, 129, 133, 134, 145, 146, 155, 158, 159, 166, 169, 177, 178, 226, 235, 237, 247, 249, 259, 267, 278, 289, 299, 334, 335, 339, 346, 355, 358, 377, 445, 446

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[1000], Plus@@Last/@FactorInteger[ # ]==2&&OrderedQ[IntegerDigits[ # ]]&]
Select[Range[500], PrimeOmega[#]==2&&OrderedQ[IntegerDigits[#]]&] (* Harvey P. Dale, Feb 16 2026 *)

Crossrefs

Sequence in context: A288379 A112381 A182150 * A135355 A350069 A245383

Adjacent sequences: A108631 A108632 A108633 * A108635 A108636 A108637

Keyword

nonn,base

Author

Zak Seidov, Jun 14 2005

Status

approved