# real analysis – What unary operation on sequences produces the sequence of pairwise sums?

Given a sequence $$(a, b, c,…)$$:

• The partial difference operator produces the sequence $$(b-a, c-b, …)$$, and
• The partial summation operator produces the sequence $$(a, a+b, a+b+c, … )$$

What about the sequence $$(a+b, b+c, c+d, …)$$?