A075817 - OEIS

A075817

Palindromic even numbers with an odd number of prime factors (counted with multiplicity).

2, 8, 44, 66, 212, 222, 242, 252, 272, 282, 292, 404, 434, 464, 474, 494, 606, 616, 646, 656, 696, 828, 848, 888, 2222, 2552, 2882, 4004, 4224, 4334, 4554, 4664, 4884, 4994, 6006, 6226, 6336, 6446, 6886, 6996, 8118, 8228, 8338, 8558, 8778, 8888, 8998

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..47.

EXAMPLE

8=2^3, 222=2*3*37 and 4004=2^2*7*11*13 are palindromic, even and products of an odd number of prime factors.

MAPLE

test := proc(n) local d; d := convert(n, base, 10); return ListTools[Reverse](d)=d and type(numtheory[bigomega](n), odd); end; a := []; for n from 2 to 21000 by 2 do if test(n) then a := [op(a), n]; end; od; a;

CROSSREFS

Cf. A046470.

Sequence in context: A324670 A334335 A283416 * A374673 A264565 A018985

Adjacent sequences: A075814 A075815 A075816 * A075818 A075819 A075820

KEYWORD

nonn,base

AUTHOR

Jani Melik, Oct 13 2002

EXTENSIONS

Edited by Dean Hickerson, Oct 22 2002

STATUS

approved