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A075799 Palindromic numbers which are products of an even number of distinct primes. 0
1, 6, 22, 33, 55, 77, 111, 141, 161, 202, 262, 303, 323, 393, 454, 505, 515, 535, 545, 565, 626, 707, 717, 737, 767, 818, 838, 858, 878, 898, 939, 949, 959, 979, 989, 1111, 1441, 1661, 1991, 2002, 2442, 3003, 3113, 3223, 3443, 3883, 4774, 5005, 5115, 6666 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..50.

EXAMPLE

1, 111=3*37 and 858=2*3*11*13 are palindromic and products of an even number of distinct primes.

MAPLE

test := proc(n) local d; d := convert(n, base, 10); return ListTools[Reverse](d)=d and numtheory[mobius](n)=1; end; a := []; for n from 1 to 7000 do if test(n) then a := [op(a), n]; end; od; a;

CROSSREFS

Cf. A046392, A002385, A069217, A032350, A030229.

Sequence in context: A015709 A020195 A035134 * A046392 A046408 A123017

Adjacent sequences:  A075796 A075797 A075798 * A075800 A075801 A075802

KEYWORD

nonn,base

AUTHOR

Jani Melik, Oct 13 2002

EXTENSIONS

Edited by Dean Hickerson, Oct 21 2002

STATUS

approved

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Last modified March 19 23:02 EDT 2019. Contains 321343 sequences. (Running on oeis4.)