|
Search: id:A075815
|
|
|
| A075815 |
|
Palindromic odd composite numbers with an odd number of prime factors (counted with multiplicity). |
|
+0
1
|
|
| 99, 171, 333, 343, 363, 555, 575, 595, 747, 777, 909, 969, 1001, 1221, 1331, 1551, 1771, 3333, 3553, 5335, 5445, 5555, 5665, 5775, 5885, 5995, 7337, 7557, 7667, 7777, 7887, 9009, 9339, 9559, 9669, 9779, 9889, 11211, 11511, 11711, 11811, 12121
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
EXAMPLE
|
5445=3^2*5*11^2 and 5555=5*11*101 are palindromic, odd, composite, and have 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) and not isprime(n); end; a := []; for n from 1 to 13000 by 2 do if test(n) then a := [op(a), n]; end; od; a;
|
|
CROSSREFS
|
Cf. A046389.
Adjacent sequences: A075812 A075813 A075814 this_sequence A075816 A075817 A075818
Sequence in context: A064112 A126230 A055164 this_sequence A075814 A097599 A033674
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
Jani Melik (jani_melik(AT)hotmail.com), Oct 13 2002
|
|
EXTENSIONS
|
Edited by Dean Hickerson (dean(AT)math.ucdavis.edu), Oct 21 2002
|
|
|
Search completed in 0.002 seconds
|
