Urgent, help me. In the arithmetic sequence {an}, A2 = 2 and A4 = 4 are known. Find the general term formula of {an} and the sum of the first five terms of {an}

Urgent, help me. In the arithmetic sequence {an}, A2 = 2 and A4 = 4 are known. Find the general term formula of {an} and the sum of the first five terms of {an}

a4-a2=2d
d=1
a1=a2-d=1
So an = n
Sn=(1+n)n/2

It is known that the first term of the sequence {an} is 1, and the later terms are given by the formula a (n-1) = 2an-2. Write out the first five terms and the general term formula of the sequence

a(n-1) = 2an-2
2(an-2) = a(n-1) -2
an-2 = (1/2)[ a(n-2) -2 ]
=>{An-2} is an equal ratio sequence, q = 1 / 2
an -2 =(1/2)^(n-1).(a1-2)
=-(1/2)^(n-1)
an = 2-(1/2)^(n-1)
a2= 3/2
a3=7/4
a4=15/8
a5=31/16

It is known that the first term of the sequence {an} is 1. The following terms are given by the formula an = 1 + 1 / an-1, and the general term formula is written

An = 1 + 1 / A, an - (1 + √ 5) / 2 = (1 - √ 5) / 2 + 1 / a = [(1 - √ 5) / (2a)] [a - (1 + √ 5) / 2], ① the same method, an - (1 - √ 5) / 2 = [(1 + √ 5) / (2a] [a - (1 - √ 5) / 2], ② ① / ②, [an - (1 + √ 5) / 2] / [an - (1 - √ 5) / 2] = [(3 - √ 5) / 2] [a - (1 + √ 5) / 2] / [a - (1 - √ 5] / [a - (1 - √ 5] / [a - (1 - √ 5] / [a - (1 - √ 5] / [a - √ 5] / [a - (1 - √ 5] / [a - √