my $count = 0;
my $seqlinec = 2;
while ( <INFILE> ) {
    if ( $seqlinc eq $count ) {
        print "$_\n";
    }
    $seqlinec += 4;
}               

##</code><code>##

my $count = 0;
while ( <INFILE> ) {
    next        if ( !$count++ );   # ignore line zero, increase linecount
    print $_;
    $count = 0  if ($count >= 3);   # reset the counter once we printed line 3 
}