2G-MAR—75 G1255:35,
Date: 29 MAR 1975 O
From: CARHART
Subjeet: YOUR BRAIN
To: LEDERBERG

ect CARHART

THAT WAS A FASCINATING PUZZLE YOU COOKED UP THIS MORNING,
CHEAVENS, YESTERDAY MORNING) AND IL COULDN’T GET TO SLEEP
WITH IT UNRESOLVED, N SUBSTANTIALLY MORE THAN 20 NIX,

I FOUND A GRAPH OF 26 NODES WHICH HAS THE SYMMETRY GROUP
OF A TETRAHEDRAL CARBON OVER FOUR OF ITS NODES. IF YOU
WOULD LIKE MORE DETALL, SEE <CARHARTDJIL. BRAINTSR.

IT HAD NEVER CONSTDERED THE POSSIBILITIES OF RECREATIONAL
GRAPH THEORY!

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