Checking for prime number in boolean expression without defining a function

Question

Could the following PL/SQL code be completed by providing some boolean expression for IF statement?

declare
   N int := extract(year from sysdate);
begin
   if INSERT_YOUR_BOOLEAN_EXPRESSION_HERE then
      dbms_output.put_line('Current year is prime number.');
   else
      dbms_output.put_line('Current year is not prime number.');
   end if;
end;

Obviously, you can't define your own function.
Only standard Oracle 11g PL/SQL functions are allowed.
The code should work properly during years 2014-9999.

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EDIT :
Answer is accepted, but problem is not solved as it was desired.
So, let's go on.

Let's reduce time interval to just 256 years in nearest future: 2014-2269
Will you be able to find another solution, more clever and more compact, without external dependencies outside Oracle server?
It requires some bright idea to succeed in this task.

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EDIT #2 :
The current record is 41 symbols long: not regexp_like(rpad(1,N,1),'^(11+)\1+$')
Now may be someone can provide even more brilliant solution?
I would be impressed enough to award one more king-size bounty ))
Beat the current record by at least 1 symbol.

Answer 1

Ok, here is another solution:

declare
N int := extract(year from sysdate);
begin
if not regexp_like(rpad('1', N, '1'),'^1?$|^(11+?)\1+$')
then
   dbms_output.put_line('Current year is prime number.');
else
   dbms_output.put_line('Current year is not prime number.');
end if;
end;

It is good up to 32767 (size of varchar2 in PL/SQL)

Answer 2

Second Attempt - 40 characters

regexp_instr(rpad(2,N+1),'2(  +)\1+$')=0

Based on @vav's answer, with a few minor changes. Replacing not regexp_like... with regexp_count...=0 saves one character. The other changes are cosmetic - replacing the character 1 with 2 to distinguish between the character and the backreference; using N+1, the default rpad parameter, and spaces just to show a slightly different way to do it. regexp_count could also work here but that function is newer than other regular expression functions.

First Attempt - 54 characters

Here is a completely impracticable solution that just so happens to use a very small number of characters for the expression (54), and in no way resembles code golf.

declare
   N int := extract(year from sysdate);
begin
   if httpuritype('goo.gl/qMu5eR').getClob like'% '||n||' %' then
      dbms_output.put_line('Current year is prime number.');
   else
      dbms_output.put_line('Current year is not prime number.');
   end if;
end;