OFFSET
1,1
LINKS
Nathaniel Johnston, Table of n, a(n) for n = 1..10000
EXAMPLE
E.g., 321 = 3*107 and 123 = 3*41 -> both 321 and 123 have two prime factors.
MAPLE
with(numtheory): read(transforms): for n from 12 to 366 do r:=digrev(n): if(not isprime(n) and not n=r and not n mod 10 = 0 and bigomega(n)=bigomega(r))then printf("%d, ", n); fi: od: # Nathaniel Johnston, Jun 23 2011
MATHEMATICA
nrnQ[n_]:=Module[{idn=IntegerDigits[n], rev}, rev=Reverse[idn]; !PrimeQ[n] &&First[rev]!=0&&idn!=rev&&PrimeOmega[n]==PrimeOmega[FromDigits[rev]]]; Select[Range[400], nrnQ] (* Harvey P. Dale, Jun 23 2011 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Patrick De Geest, Aug 15 1999
EXTENSIONS
Definition clarified by Harvey P. Dale, Jun 23 2011
STATUS
approved