Problem with SRT file (index and empty line)

How can I change the following .srt file to look like the one at the end of the post?:

1

1

00:00:01,270  -->  00:00:04,520
<v Narrator>Now before diving into some NodeJS code,</v>
2

2

00:00:04,520  -->  00:00:06,700
let's do a high level overview

I want to change it into this (not duplicate index and remove empty line):

1
00:00:01,270  -->  00:00:04,520
<v Narrator>Now before diving into some NodeJS code,</v>

2
00:00:04,520  -->  00:00:06,700
let's do a high level overview

I think I can use Notepad++ but how?

Assumming //empty line don't exist as literal

• Ctrl+H
• Find what: \R?\d+\R+(\d+\R)\R*(.+\R.+(\R?))
• Replace with: $1$2$3
• CHECK Match case
• CHECK Wrap around
• CHECK Regular expression
• UNCHECK . matches newline
• Replace all

Explanation:

\R?         # any kind of linebreak, optional
\d+         # 1 or more digits
\R+         # any kind of linebreak
(           # group 1
    \d+         # 1 or more digits
    \R          # any kind of linebreak
)           # end group
\R*         # any kind of linebreak
(           # group 2
    .+          # 1 or more any character but newline
    \R          # any kind of linebreak
    .+          # 1 or more any character but newline
    (\R?)       # group 3, any kind of linebreak, optional
)           # end group

Replacement:

$1          # content of group 1, the digits
$2          # content of group 2, the text
$3          # content of group 3, optional linebreak

Screenshot (before):

Screenshot (after):