I recommend having a baby at 36. Then there will be be 9 times when your age is an even multiple of their age. Every time, you get to say "your age is definitely a factor" which is a very important dad joke. So if your child is 0 when you are 36 then here's your age, their age and the multiple
37 = 1 x 37
38 = 2 x 19
39 = 3 x 13
40 = 4 x 10
42 = 6 x 7
45 = 9 x 5
48 = 12 x 4
54 = 18 x 3
2 = 36 x 2
48 gives you 10 times but only if you make to 96!
So the math problem here is is there a limit to or can you find higher and higher numbers N such that i divide N+i for more and more values of i? I think there's no limit.. 36 and 48 have lots of 2s and 3s in them, so if i has lots of 2s and 3s so will N+i, the 5s and 7s are a lucky bonus.