Show the decimal value of a number of 1s appended with a 3 then squared

0..^8 -> each {|n|
    var k = ((10**(n+1) - 1)/9 + 2)
    say [k, k**2]
}

Output:

[3, 9]
[13, 169]
[113, 12769]
[1113, 1238769]
[11113, 123498769]
[111113, 12346098769]
[1111113, 1234572098769]
[11111113, 123456832098769]