####################################################################
# addstr - solves Schronce's Postulate for any whole number
#      Schronce's Postulate: "The sum of any series of
#      consecutive whole numbers, starting with 1, is equal to
#      the largest number multiplied by 1/2 the largest number
#      plus 1/2 the largest number."
#
#      Example: 1 +2 +3 +4 +5 +6 +7 +8 + 9 +10 = 55
#      Using Schronce's Postulate: (10 * 5) + 5 = 55
#
# J. David Schronce
####################################################################
if [[ $1 = "" ]]; then
  echo "\nUSAGE: $0 <highest number in series>\n"
  exit
fi
echo "(($1 * ($1 * .5)) + ($1 * .5))" | bc