Allene:
H₂C=C=CH₂,
In it central carbon is sp hybrised while left carbon is sp² hybridised.
So there is a presence of three sigma and one pi bond on the left bonded carbon of allene.
And there is a presence of sp² hybridised orbital on the left most carbon of allene. or we can say there is presence of 3 sigma and one pi bonding orbitals on the left most carbon of allene.