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A108635 Semiprimes with property that digits are in non-increasing order. 1
4, 6, 9, 10, 21, 22, 33, 51, 55, 62, 65, 74, 77, 82, 85, 86, 87, 91, 93, 94, 95, 111, 221, 321, 411, 422, 511, 533, 542, 543, 551, 553, 554, 611, 622, 633, 655, 662, 721, 731, 753, 755, 763, 766, 771, 831, 841, 842, 843, 851, 862, 865, 866, 871, 886, 921, 922 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..57.

EXAMPLE

The semiprime 14 is missing because 4>1.

MATHEMATICA

Select[Range[1000], Plus@@Last/@FactorInteger[ # ]\[Equal]2&&OrderedQ[Reverse[IntegerDigits[ # ]]]&]

CROSSREFS

Cf. A108634.

Sequence in context: A087112 A077554 A118778 * A071964 A135257 A118697

Adjacent sequences:  A108632 A108633 A108634 * A108636 A108637 A108638

KEYWORD

nonn,base,easy,less

AUTHOR

Zak Seidov, Jun 14 2005

STATUS

approved

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Last modified July 29 21:04 EDT 2014. Contains 245044 sequences.