Could be a double form of Coreopsis, at a guess.

I agree with Owdboggy :o))

Me too

Yep, double flowered Coreopsis grandiflora. It's hard to tell which variety, since there are so many.

Grandiflora ‘Sunset’ perhaps?

C. g. 'Early Sunrise', more likely, though there are many varieties more or less like that.

Thank you very much to all who replied. I really appreciate it.