I never had that combination. I'm sure someone that has will be jumping in, but I did have 2 trucks with 5 and 2's that had an irregular sequence.

They were,

1 Lo
1 Hi
2 Lo
2 Hi
3 Lo
3 Hi
4 Lo
5 Lo
4 Hi
5 Hi


'60-'72 Chev/GMC Fan
GMC 9500 Fan
Detroit Diesel Fan