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A046393 Palindromes with exactly 3 distinct prime factors. 2
66, 222, 282, 434, 474, 494, 555, 595, 606, 646, 777, 969, 1001, 1221, 1551, 1771, 2222, 2882, 3333, 3553, 4334, 4994, 5335, 5555, 5665, 5885, 5995, 6226, 6446, 6886, 7337, 7557, 7667, 7777, 7887, 8338, 8558, 8998, 9339, 9669, 9779, 9889, 11211 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The terms must have only three distinct prime factors even when counted with multiplicity.  For example, 252 is not a term even though (1) it is a palindrome and (2) only three distinct primes occur when it is factored, because 252 = 2*2*3*3*7. - Harvey P. Dale, Aug 29 2016

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[Range[12000], #==IntegerReverse[#]&&PrimeNu[#]==PrimeOmega[#]==3&] (* Harvey P. Dale, Aug 29 2016 *)

CROSSREFS

Cf. A046329, A046409.

Sequence in context: A202640 A074873 A205817 * A268582 A117306 A158070

Adjacent sequences:  A046390 A046391 A046392 * A046394 A046395 A046396

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Jun 15 1998.

STATUS

approved

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Last modified August 20 03:34 EDT 2017. Contains 290823 sequences.