Prob #2
FTduo:=proc() local ALPH,T1,W,DB,C,B,FL,L,A,FL1,S1,ALPH2,i,j,C2,C3:
ALPH:=[a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z]:
ALPH2:=[]:
for i from 1 to nops(ALPH) do
 for j from i+1 to nops(ALPH) do
  ALPH2:=[op(ALPH2),[ALPH[i],ALPH[j]]]:
  od: 
od:


DB:=ENG():
C:=0:
for L in ALPH2 do
 T1[L]:=0:
od:


for A from 1 to 28 do
 for W in DB[A] do
  for B from 1 to nops(W)-1 do
    T1[[W[B],W[B+1]]]:=T1[[W[B],W[B+1]]]+1:
    C:=C+1:
  od:
 od:
od:


C2:=0: 
C3:=0:
for L in ALPH2 do
  if T1[L] > 0 then
     C2:=C2+1:
  fi:
  if T1[L] > 10 then
     C3:=C3+1:
  fi:
od:
C2,C3:
end:


Test run
FTduo();
                            244, 208


FTtrio:=proc() local ALPH,T1,W,DB,C,B,FL,L,A,FL1,S1,ALPH2,i,j,k,C2,C3:
ALPH:=[a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z]:
ALPH2:=[]:
for i from 1 to nops(ALPH) do
 for j from i+1 to nops(ALPH) do
  for k from i+2 to nops(ALPH) do
   ALPH2:=[op(ALPH2),[ALPH[i],ALPH[j],ALPH[k]]]:
   od: 
  od: 
od:


DB:=ENG():
C:=0:
for L in ALPH2 do
 T1[L]:=0:
od:


for A from 1 to 28 do
 for W in DB[A] do
  for B from 1 to nops(W)-2 do
    T1[[W[B],W[B+1],W[B+2]]]:=T1[[W[B],W[B+1],W[B+2]]]+1:
    C:=C+1:
  od:
 od:
od:


C2:=0: 
C3:=0:
for L in ALPH2 do
  if T1[L] > 0 then
     C2:=C2+1:
  fi:
od:
C2:
end:


Test run
FTtrio();
                           1337