An solution of Vczh's problem

guess.moe

var MakeTest(a0, d):
    var j = 0;
    return (x) =>
        def r = a0 + d * j;
        j += 1;
        return x === r

def guess(test):
    var counter = 0
    for var segment in 1..infinity:
        for var term in 1...segment:
            for var mod in 0..term:
                var testA0 = (segment - term) * term + mod
                var testD  = term
                if test (counter * testD + testA0):
                    tracel ('found ' + testA0 + ', ' + testD)
                counter += 1
                
-- testing
guess MakeTest(555, 19)