The number of species from the following carrying a single lone pair on central atom Xenon is
$$XeF_5^+$$, $$XeO_3$$, $$XeO_2F_2$$, $$XeF_5^-$$, $$XeO_3F_2$$, $$XeOF_4$$, $$XeF_4$$

We need to find how many species from the given list carry a single lone pair on the central atom Xenon. Xenon has 8 valence electrons, and we count lone pairs by subtracting electrons used in bonding.

For $$XeF_5^+$$: Effective electrons from Xe = $$8 - 1 = 7$$ (charge adjusts by $$-1$$). Five Xe-F bonds use 5 electrons, leaving $$7 - 5 = 2$$ electrons = 1 lone pair. Geometry is square pyramidal with $$sp^3d^2$$ hybridization.

For $$XeO_3$$: Three double bonds use $$3 \times 2 = 6$$ electrons, leaving $$8 - 6 = 2$$ electrons = 1 lone pair. Geometry is trigonal pyramidal with $$sp^3$$ hybridization.

For $$XeO_2F_2$$: Two double bonds with O use 4 electrons and two single bonds with F use 2 electrons, totalling 6. That leaves $$8 - 6 = 2$$ electrons = 1 lone pair. Geometry is see-saw with $$sp^3d$$ hybridization.

For $$XeF_5^-$$: Effective electrons = $$8 + 1 = 9$$. Five bonds use 5, leaving 4 electrons = 2 lone pairs. This does not qualify.

For $$XeO_3F_2$$: Three double bonds use 6 and two single bonds use 2, totalling 8. That leaves $$8 - 8 = 0$$ lone pairs. This does not qualify.

For $$XeOF_4$$: One double bond uses 2 and four single bonds use 4, totalling 6. That leaves $$8 - 6 = 2$$ electrons = 1 lone pair. Geometry is square pyramidal with $$sp^3d^2$$ hybridization.

For $$XeF_4$$: Four single bonds use 4 electrons, leaving $$8 - 4 = 4$$ electrons = 2 lone pairs. This does not qualify.

The species with a single lone pair are $$XeF_5^+$$, $$XeO_3$$, $$XeO_2F_2$$, and $$XeOF_4$$. Hence, the answer is $$4$$.