the main connections should be:
IC-A Ostend - Eupen = HLE13 (or HLE 18) + 12 HV I11 (sometimes mixed with I6 or I10)
IC-B+ Brussels - Amsterdam = HLE 28 + 7 HV NS (and 1 train with Oebb coaches)
IC-C Ostend - Kortrijk = some services with HLE 21 + HV M4m
IC-E Tongeren - Knokke/Blankenberge = most services with HLE 27 + HV M6 + HLE 27 + HV M6 (the 2 sets of loc and coaches are split/coupled in Bruges using automaic GF couplers)
IC-F Quiévrain - Liége Guillemins = HLE 21 + HV M4m or HLE 27 + HV M6 (sometimes they get an extra push by an HLE 23 to help them climb the hill Liége - Ans)
IC-H Mouscron - Schaarbeek = HLE 21 + HV M4m
IC-I Antwerpen - Charleroi = HLE 27 + 8 HV M6
IC-K Gent SP - Genk = HLE 27 + 8 HV M6
IC-N Charleroi - Essen = HLE 27 + 8 HV M6
IC-O Brussel - Maastricht = HLE 13 + 8 or 12 HV I11
IR-f Kortrijk - Mechelen (- Leuven) = HLE 21 + 5 HV M4m
IR-J Quévy - Brussels Airport = 2 out of 4 trains HLE 27 + 8 M6
IR-l Binche - Louvain-la-neuve= HLE26 + 8HV M6 + HLE26
IR-m Liers - Luxembourg = CFL HLE3000 + 3 HV I10 or I6
IR-n Antwerpen - Brussels = peaktime trains with HLE 21 + 6 HV M5m
IR-s Antwerpen - Noorderkempen = 2HV M6 + HLE13 + 2HV M6
those are the main services operated by loco-hauled trains, do note that most peak-hour trains are also loco-hauled, often with old locomotives and exotic coach combinations and that on most IC and IR services the busiest trains are operated using M6 double-deck stock
for more information concerning train compostitions check:
http://www.beluxtrains.net