MR-830 / 830. problem

limn1+2n+1n

limn1+2n+1n

1t=2n+1

t=n+12

2·t=n+1

n+1=2·t

n=2·t-1

nt

limn1+2n+1n

=limt1+1t2t-1

=limt1+1t2t·1+1t-1

=limt1+1tt·2·1+1t-1

=1+1·2·1+1-1

=e2·1+0-1

=e2