I had the opposite problem using meetup.com in the suburbs to meet young people like myself. For example, I would go to salsa or swing dancing meet-ups and all of the people would be couples in your 40 to 60 range. So maybe try that?

Just curious, why exactly do you want to meet people twice your age?

For many reasons I often hung out with people much older than me. I am the only one of my age range in my family so I guess I was always surrounded by adults. I am appalled by calm diners more than bars. Also I like questioning people's experience, and I'm currently in a place where I have many questions about later life and I don't have a sufficient sample of people similar to me, just older, to talk about that sort of stuff.

I just really enjoy the interactions I have with older adults...

Also an irony in criticizing both devalued community and people living at home in their twenties/thirties. In many (most?) non-American cultures, emphasizing collectivist/communal values goes hand-in-hand with living at home in your twenties, which is deemed perfectly normal. In fact, I would say it's more abnormal on a global scale to kick your kids out at 18.