It follows that each coset of the group of Appell sequences contains exactly one sequence of binomial type .
The group of Sheffer sequences is a semidirect product of the group of Appell sequences and the group of sequences of binomial type .
group follows that each coset of the group of Appell sequences contains exactly one sequence of binomial type .
The group of Sheffer sequences is a semidirect product of the group of Appell sequences and the group of sequences of binomial type .