I remember a short story in which "aliens" appear at a man's door looking for a Mr. Potts. His name is Calderone. They're from the future, sent by his then-adult son, and are there to train him to be even more supergenius.
I read this in the early 70s, in an anthology, I think. Anyone remember it?
This is almost definitely "When the Bough Breaks" (1944) by "Lewis Padgett" (Henry Kuttner and C. L. Moore).
The little people from the future are looking for "Mr. Pott:"
The last lessee, an insurance man who drank heavily, moved out one day talking about little men who came ringing the bell at all hours asking for a Mr. Pott, or somebody like that. Not until some time later did Joe identify Pott with Cauldron—or Calderon.
The men from the future (not aliens, though odd-looking) show up:
Four tiny men were standing in the hall. That is, they were tiny below the brows. Their craniums were immense, watermelon large and watermelon shaped, or else they were wearing abnormally huge helmets of glistening metal. Their faces were wizened, peaked tiny masks that were nests of lines and wrinkles. Their clothes were garish, unpleasantly colored, and seemed to be made of paper.
"Oh?" Calderon said blankly.
Swift looks were exchanged among the four. One of them said, "Are you Joseph Calderon?"
"Yeah."
"We," said the most wrinkled of the quartet, "are your son's descendants. He's a super child. We're here to educate him."
Also matching your memory, Alexander (the child) himself sent them back to educate him:
"Lord knows," Calderon said. He moistened his lips. "What kind of a gag is that? Who sent you?"
"Alexander," Bordent said. "From the year... ah... about 2450, reckoning roughly. He's practically immortal. Only violence can kill one of the Supers, and there's none of that in 2450."
