Fire-Water: Fire, Ice, Steel
1 Pokemon
Fire-Electric: Steel
1 Pokemon
Fire-Fighting: Bug
7 Pokemon
Fire-Flying: Grass, Bug
6 Pokemon
Fire-Bug: Grass
2 Pokemon
Fire-Rock: Fire
1 Pokemon
Fire-Ghost: Bug
3 Pokemon
Fire-Dragon: Fire, Grass
2 Pokemon
Fire-Steel: Grass, Ice, Bug, Steel, Fairy
1 Pokemon
Water-Electric: Steel
3 Pokemon
Water-Grass: Water
3 Pokemon
Water-Ice: Ice
6 Pokemon
Water-Rock: Fire
10 Pokemon
Water-Dragon: Water, Fire
2 Pokemon
Water-Steel: Ice, Steel
1 Pokemon
Electric-Grass: Electric
1 Pokemon
Electric-Dragon: Electric
2 Pokemon
Electric-Steel: Flying, Steel
3 Pokemon
Grass-Poison: Grass
15 Pokemon
Grass-Flying: Grass
5 Pokemon
Grass-Bug: Grass, Ground
6 Pokemon
Grass-Steel: Grass
2 Pokemon
Fighting-Poison: Bug
2 Pokemon
Fighting-Flying: Bug
1 Pokemon
Fighting-Dark: Dark
3 Pokemon
Fighting-Steel: Bug, Rock
3 Pokemon
Poison-Ground: Poison
2 Pokemon
Poison-Flying: Grass, Bug, Fighting
3 Pokemon
Poison-Bug: Grass, Fighting
12 Pokemon
Poison-Ghost: Poison, Bug
4 Pokemon
Poison-Dragon: Grass
1 Pokemon
Ground-Rock: Poison
9 Pokemon
Ground-Ghost: Poison
2 Pokemon
Ground-Steel: Rock
3 Pokemon
Flying-Psychic: Fighting
6 pokemom
Flying-Bug: Grass, Fighting
4 porkmon
Flying-Ghost: Bug
2 Pokemon
Flying-Dragon: Grass
6 Pokemon
Flying-Steel: Grass, Bug
1 Pokemon
Flying-Fairy: Fighting, Bug
2 Pokemon
Psychic-Steel: Psychic
6 Pokemon
Psychic-Fairy: Fighting
6 Pokemon
Bug-Steel: Grass
7 Pokemon
Rock-Dragon: Fire
2 Pokemon
Rock-Steel: Normal, Flying
6 Pokemon
Ghost-Steel: Bug
4 Pokemon
Dragon-Steel: Grass
1'pokemon
Steel-Fairy: Bug
3 Pokemon
I only put combos with actual Pokemon who have that type. Here, the opposite combo is the same. Example: I only put Fire-Water and not Water-Fire.
Source, where I just looked around the page