 Humbert series

In mathematics, Humbert series are a set of seven hypergeometric series Φ1, Φ2, Φ3, Ψ1, Ψ2, Ξ1, Ξ2 of two variables that generalize Kummer's confluent hypergeometric series 1"F"1 of one variable and the confluent hypergeometric limit function 0"F"1 of one variable.The first of these double series was introduced by .