What part of the country are you in? 
Sigh… Unfortunately the part to the north of you, which is in fact a different country altogether.
Heterosexual 18 year old male. 15/16 to late twenties.
Female, 57, have dated men as young as 26 ( 28 years younger at the time) and up to my own age. I wouldn’t really deliberately go into the pool of the 20’s again but it was nice and I would not rule it out completely. Mostly the guys I am attracted to are 40 to 55, old enough to have some maturity, but not old yet, lol. The only time in my life I dated a man older than I was in college, when I was 18.
I’m 59. I’d at least consider dating anyone from age 20 to age 80.
A friend of mine married a man 20 years her elder.
Not working out all too well: he can’t keep up with her (walking, I meant, but in other ways too.)
I’m male, and would prefer to date someone my own age or slightly younger – but not so young that I’d fade in the stretch and leave her tempted to seek out a younger guy.
Basically, she has to say yes also. (At this point in life, I’d consider anyone who would say yes.)