RosettaCodeData/Task/Motzkin-numbers/PascalABC.NET/motzkin-numbers.pas
2025-02-27 18:35:13 -05:00

31 lines
738 B
ObjectPascal

function IsPrime(n: int64): boolean;
begin
if (n = 2) or (n = 3) then Result := true
else if (n <= 1) or ((n mod 2) = 0) or ((n mod 3) = 0) then Result := false
else
begin
var i := 5;
Result := False;
while i <= trunc(sqrt(n)) do
begin
if ((n mod i) = 0) or ((n mod (i + 2)) = 0) then exit;
i += 6;
end;
Result := True;
end;
end;
function mot(): sequence of biginteger;
begin
var (a, b, n) := (0bi, 1bi, 1bi);
repeat
yield b div n;
n += 1;
(a, b) := (b, (3 * (n - 1) * n * a + (2 * n - 1) * n * b) div ((n + 1) * (n - 1)))
until false;
end;
begin
foreach var val in mot.Take(42) index i do
writeln(i:2, val:20, if isprime(int64(val)) then ' is prime' else '');
end.