Question

9结尾的质数~~

求1000以内以9结尾的质数，如19，29，59，79，89，……

Answer 1

19.29.59.79.89.109.139.149.179.199.209.229.239.269.319.349.359.379.389.409.419.439.449.479.499.509.569.589.599.619.649.659.709.719.739.769.809.829.839.859.869.899.919.929.979.989

Answer 2

1000以内9结尾的质数
19.29.59.79.89.109.139.149.179.199.209.229.239.269.319.349.359.379.389.409.419.439.449.479.499.509.569.589.599.619.649.659.709.719.739.769.809.829.839.859.869.899.919.929.979.989

Answer 3

19.29.59.79.89.109.139.149.179.199.229.239.269.349.353.359.367.373.379389.409.419.439.449.479.499.509.569.599.619.659.709.719.739.769.809.
829.839.859.919.929

Answer 4

用matlab
function p=findprime()
p=[];
for i=3:2:999
if isPrime(i)==1 & mod(i,10)==9
p=[p,i];
end
end

function t=isPrime(i)
if i==2
t=1;
return;
end
if mod(i,2)==0
t=0;
return;
end
m=sqrt(i);
for j=3:2:m
if mod(i,j)==0
t=0;
return;
end
end
t=1;

p =

Columns 1 through 12

19 29 59 79 89 109 139 149 179 199 229 239

Columns 13 through 24

269 349 359 379 389 409 419 439 449 479 499 509

Columns 25 through 36

569 599 619 659 709 719 739 769 809 829 839 859

Columns 37 through 38

919 929