Euler--Maclaurin and Poisson analogues of the summations ∑a<n≤bχ(n)f(n), ∑a<n≤bd(n)f(n), ∑a<n≤bd(n)χ(n)f(n) have been obtained in a unified manner, where (χ(n)) is a
periodic complex sequence; d(n) is the divisor function and f(x) is a
sufficiently smooth function on [a,b]. We also state a generalised Abel's
summation formula, generalised Euler's summation formula and Euler's summation
formula in several variables.Comment: 9 page