There are two kinds, “ 1 + 1 + 3 “and “ 1 + 2 + 2 “ which are ways of representing 5 by the sum total of three integers other than zero.
“ 1 + 3 + 1 “ is considered as the same kind as “ 1 + 1 + 3 “.
Moreover, in the case of 7, there are four kinds, “1 + 1 + 5 “, “ 1 + 2 + 4 “, “ 1 + 3 + 3 “, and “ 2 + 2 + 3 “.
How many kinds of the way to represent 9 are there?
“ 1 + 3 + 1 “ is considered as the same kind as “ 1 + 1 + 3 “.
Moreover, in the case of 7, there are four kinds, “1 + 1 + 5 “, “ 1 + 2 + 4 “, “ 1 + 3 + 3 “, and “ 2 + 2 + 3 “.
How many kinds of the way to represent 9 are there?
Answer
7 kinds
