Prime numbers p for which the sum of primes less than or equal to p is prime: Difference between revisions
Content added Content deleted
m (changed "prime numbers" ---> "primes", added whitespace.) |
(Added XPL0 example.) |
||
Line 186: | Line 186: | ||
Found 21 such primes. |
Found 21 such primes. |
||
</pre> |
|||
=={{header|XPL0}}== |
|||
<lang XPL0>func IsPrime(N); \Return 'true' if N is a prime number |
|||
int N, I; |
|||
[if N <= 1 then return false; |
|||
for I:= 2 to sqrt(N) do |
|||
if rem(N/I) = 0 then return false; |
|||
return true; |
|||
]; |
|||
int Count, N, M, Sum; |
|||
[Count:= 0; |
|||
for N:= 2 to 1000-1 do |
|||
if IsPrime(N) then |
|||
[Sum:= 0; |
|||
for M:= 2 to N do |
|||
if IsPrime(M) then |
|||
Sum:= Sum + M; |
|||
if IsPrime(Sum) then |
|||
[IntOut(0, N); |
|||
Count:= Count+1; |
|||
if rem(Count/10) = 0 then CrLf(0) else ChOut(0, 9\tab\); |
|||
]; |
|||
]; |
|||
CrLf(0); |
|||
IntOut(0, Count); |
|||
Text(0, " such numbers found below 1000. |
|||
"); |
|||
]</lang> |
|||
{{out}} |
|||
<pre> |
|||
2 3 7 13 37 43 281 311 503 541 |
|||
557 593 619 673 683 733 743 839 881 929 |
|||
953 |
|||
21 such numbers found below 1000. |
|||
</pre> |
</pre> |