read WILF:
 
 
 
print(`The set of forbidden pattern is`):
print({[1,2,3,4],[2,1,3]});
 
print(`This is the (RIGOROUS) scheme`):
 
gu:=Scheme({[1,2,3,4],[2,1,3]},4):
 
print([gu[1],gu[2],op(gu[3]),op(gu[4]),op(gu[5])]):
 
print(`This is the sequence`):
 
SchemeSeries(gu,25);
 
print(`This is the (Semi-Rigorous) Recurrence `):
 
factor(SchemeRecurrence(gu,n,N,25));
 
quit: