Pensar en

Pensar en
 

Voy a pasar quince días con mis amigos en Madrid y estamos pensando en ir a un partido de fútbol.

Do we need the preposition ‘en’ in the above sentence?
I know we tend to say: pensamos ir a un partido…

Many thanks in advance.

According to the RAE, "pensar algo" is used when you have the intention of doing something; when you say "pensar en algo" is better when you are remembering or reflecting on something. :)
Personally, I think you can use it both ways, because you either have the intention or are considering to do that activity... for me, it wouldn't change the meaning significatively either. :thinking:

Thank you so much, AngelicaDeAlquezar.