N,S,K=map(int,input().split())
S-=K*N*(N-1)//2-1
if S==0:
  print(1)
  exit()
m=10**9+7
r=range
D=[[0]*(S+1) for i in r(N+1)]
D[0][0]=1
for i in r(N):
  for j in r(S):
    k=j
    while k<=S:
      D[i+1][k]=D[i][j]+D[i+1][k]%m
      k+=i+1
print(D[-1][S-1]%m)