

A075800


Palindromic numbers which are products of an odd number of distinct primes.


1



2, 3, 5, 7, 11, 66, 101, 131, 151, 181, 191, 222, 282, 313, 353, 373, 383, 434, 474, 494, 555, 595, 606, 646, 727, 757, 777, 787, 797, 919, 929, 969, 1001, 1221, 1551, 1771, 2222, 2882, 3333, 3553, 4334, 4994, 5335, 5555, 5665, 5885, 5995, 6006, 6226, 6446
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OFFSET

1,1


LINKS

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


EXAMPLE

191 is palindromic and prime, 222=2*3*37 is palindromic and a product of 3 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. A002385, A069217, A032350, A030059.
Sequence in context: A004089 A092791 A070892 * A067909 A323697 A103850
Adjacent sequences: A075797 A075798 A075799 * A075801 A075802 A075803


KEYWORD

nonn,base


AUTHOR

Jani Melik, Oct 13 2002


EXTENSIONS

Edited by Dean Hickerson, Oct 21 2002


STATUS

approved



