Am gasit o solutie, nu e cea mai eficienta, probabil se face mult mai usor, dar momentan asta e singura care mi-a mers :
for(i=0;i<5;i++)
for(j=0;j<7;j++)
{ if (i==0 || j==6)
a[i][j]=1;
if (i==1)
a[i][j]=7-j;
if (j==5)
a[i][j]=i+1; }
for(i=0;i<5;i++)
{ for(j=0;j<7;j++)
{ if(a[i][j]==0 && a[i-1][j]!=0 && a[i][j+1]!=0)
a[i][j]=(a[i-1][j]+a[i][j+1])%10; }
for(j<7; j>=0; j--)
if(a[i][j]==0)
a[i][j]=(a[i-1][j]+a[i][j+1])%10; }