@Kitonum  Jesus christ, I am an idiot. Thanks a lot - still annoyed that simplify couldn't figure that one out tho. 

@Rouben Rostamian  The sequence should be 1,2,6,18,54

@Joe Riel  f(4) should be equal to 54 which I'm not getting via this :( 

@vv 

This does indeed return the correct as provided by my textbook, however, I really can't seem to follow your idea, or whatever it is you're doing. Could you explain, or is there an even simpler way of doing this?

Also, thanks

@nm 

Yeah, I suppose that makes sense. However, I can't just make up a condition, if you know what I mean. 

This is an example from a textbook that I'm trying to follow, but I cannot seem to grasp how they got it through (no syntax is provided)...

@nm

Hey - A 4th ODe does not need 4 boundary conditions. I do know that what I'm typing with the D(y)(infinity)=0 is wrong... This is what I'm trying to get help with.. How do i insert the condition with the limit as t -> infinity it needs to = 0. 

@brian bovril 

That works fantastic, with the direct search package, how would one do it for the global minimum then? Thanks!