Shorten an already short mathematical expression

Emotinomicon, 48 bytes / 13 characters

I do it, not because it is short, but because it is fun. Try it here. You'll have to copy+paste it into the textbox.

⏪✖➕⏩

Explanation:

  ⏪       ✖       ➕         ⏩   explanation
                                              take numeric input
    ⏪                                           open loop
                                              duplicate top of stack
                                              push pi
                ✖                               multiply top two elements on stack
                                              reverse stack
                                              pop N, push e^N
                            ➕                   add top two elements on stack
                                              take numeric input
                                              duplicate top of stack
                                              pop N, push N+1
                                            ⏩   close loop

Here is the program in its native environment, the mobile phone: the image


Dyalog APL, 3 characters

As a tacit phrase.

○+*

Monadic multiplies its argument with π, monadic * is the exponential function exp. ○+* is a train such that (○+*)ω is equal to (○ω)+(*ω). Since this is APL, the phrase works for arguments of arbitrary shape, e. g. you can pass a vector of arbitrary length.

The same solution is possible in J as o.+^ with o. being and ^ being *.


R, 25 24 bytes

cat(exp(x<-scan())+pi*x)    

Is this it? It gets input from user, assign it to x, calculates its exponential multiply it to pi, and finally cat()prints the result.

edit: 1 bytes saved thanks to Alex A.