A119974 Embed zeros in A119972; thereby creating a signed triangular matrix illustrating the pattern of negative values.

1, 2, -3, 4, 0, 5, 0, -6, 0, -7, 8, 0, 0, 0, 9, 0, 0, 10, 0, 0, -11, 0, -12, 0, 0, 0, 0, 13, 0, 0, 0, -14, 0, 0, 0, -15, 16, 0, 0, 0, 0, 0, 0, 0, 17, 0, 0, 0, 0, 18, 0, 0, 0, 0, -19, 0, 0, 20, 0, 0, 0, 0, 0, 0, 0, 21