Adjectives

(s)back-to-back, consecutiveone after the other“back-to-back home runs”
(s)consecutive, sequent, sequential, serial, successivein regular succession without gaps“serial concerts”
(s)straight, consecutivesuccessive (without a break)“sick for five straight days”

Adverbs

(r)consecutive, sequentiallyin a sequential manner“we numbered the papers consecutively”