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You're thanking me for a clear explanation I gave two or more years ago, right?
vamos = we go, we do go, we're going (slang: let's go)
vámonos = slang: let's go
vayámonos = let's go (This is the only form that really translates to the first-person, plural imperative "let's go," but the slang forms are very commonly used and, therefore, are correctly translated as "let's go".)

Thank you for the clear explanation regarding vamos - vamanos - vayanos
I learned Spanish in Europe back in the 70s and worked in the South of Spain for a while but did not remember ever hearing the vamanos/vayanos until I came to Texas.
I always thought it was a Mexican thing (as differentiating Latin American Spanish to Castillian Spanish)