%I #8 Oct 16 2024 16:53:34
%S 4,6,22,202,262,454,626,818,838,878,898,20302,20602,22322,22522,22622,
%T 22822,24142,24842,26662,26762,28682,41014,41414,41614,41714,43034,
%U 43234,43534,43634,45454,45554,45754,47074,47374,47774,49094,49394
%N Palindromic even numbers with exactly 2 prime factors (counted with multiplicity). Equivalently, palindromic numbers of the form 2*p with p prime.
%e 4=2^2, 6=2*3 and 22=2*11 are palindromic, even and have exactly 2 prime factors.
%p test := proc(n) local d; d := convert(n,base,10); return ListTools[Reverse](d)=d and numtheory[bigomega](n)=2; end; a := []; for n from 2 to 50000 by 2 do if test(n) then a := [op(a),n]; end; od; a;
%t Select[Range[50000],EvenQ[#]&&PalindromeQ[#]&&PrimeOmega[#]==2&] (* _Harvey P. Dale_, Oct 16 2024 *)
%Y Cf. A001747.
%K nonn,base
%O 1,1
%A _Jani Melik_, Oct 13 2002
%E Edited by _Dean Hickerson_, Oct 21 2002