The Collaborative International Dictionary of English v.0.48:

Sequential \Se*quen"tial\, a.
   Succeeding or following in order. -- Se*quen"tial*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

sequential
    adj 1: in regular succession without gaps; "serial concerts"
           [syn: consecutive, sequent, sequential, serial,
           successive]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "sequential":
   appendant, catenary, connected, consecutive, consequent,
   consequential, consistent, continuous, cyclic, deducible,
   derivable, derivational, derivative, ensuing, final, following,
   infenible, joined, lineal, linear, next, ordered, orderly, ordinal,
   organized, posterior, postpositional, postpositive, progressive,
   proximate, resultant, resulting, sequacious, sequent, serial,
   seriate, subsequent, succeeding, successional, successive,
   suffixed, systematic, tight, uninterrupted