What nuclei are fused in the nuclear reaction of a hydrogen bomb?

Hydrogen bomb is a very strong nuclear weapon that uses a combination of both fission and fusion in order to produce a massive explosion.

Hydrogen bomb is prepared using the following reaction (which also shows the nuclei that are fused together):

H2 + H3 → He4 + n + 17.5 MeV

where:

H2 is deuterium

H3 is tritium