SAP Campus WDF 3 Mystery Cache

You’ll need the listed coordinates to calculate the coordinates of the cache. It’s not too far away.

First station:
To get the coordinates of the cache
... search a tower where "2 green (by daylight) rivers" come together (by night they are blue...)
… look at the bottom of the tower at the few blue lamps that are lit
… imagine that all the black round dots on the ground are lamps (they were at some time), count them and multiply by two

W = potential number of lights
D = Henning Kagermanns BirthDAY (xx.July)[PLEASE search this date before you start to find the cache!!!! You'll NOT find a hint over there]
F = the first odd prime number

Cache:
N49°17.(606+D+F+W/2+D*2) E008°38.(557-((W-14)*3)+29)

Pay attention:
… keep one's eyes peeled - the cache is a nano one
… if you are small please jump or take somebody with you taller than 1.75m :)

Bonus:
Do not forget do note down "c". You will need it for the bonus