Write a function called largest_sum_sequence() that accepts an array of signed integers and the number of items in the array as parameters, and returns the largest sum of a sequence of numbers in the array. A sequence is defined as a single item or multiple items that are in consecutive adjacent memory locations.

Example 1: 9 3 -1 7 -12 largest sum in sequence is 18 [9, 3, -1, 7]

Example 2: -77 3 -2 1 largest sum in sequence is 3 [3]