Relations of e (e-1, e-2 etc.)

n= 0 to ∞Σ1/n! = e

n= 1 to ∞Σ1/n! = e-1

n= 2 to ∞Σ1/n! = e-2

n= 0 to ∞Σ1/(n+1)! = e-1

n= 1 to ∞Σ1/(n+1)! = e