λ m s m (2 : 2)
to denote the n th K l -mean
of order l > 0. If s λ n → s as n ® ∞ , where s is a fixed finite number, then the sequence { s n } or the series ∑ u n is said to be summable by Kar- amata method ( K l )
of order l > 0 to the sum s ,
and we can write