That's a pretty cheesy comparison
corn isn't energy until it is turned into ethanol.
Lets use real numbers at todays prices.
Average #2 fuel oil price today delivered is $4.12 a gallon. It contains 138,000 BTU. Cost per BTU is 3 cents.
Average ethanol price today (at the refinery since there is no home delivery standard) is $2.10 a gallon and it contains 76,000 BTU. or average cost of 2.76 cents per BTU at the refinery
If you consider the additional cost of transporting ethanol (which can't go by pipeline like oil can) #2 oil still wins a head to head comparison at today's prices.
Average corn price is 3.90 a bushel in the field.