I want to display one blog article less than on the following pages. The following code works but the the paginaton on the first page displays 1, 2, 3, 4 and on the next pages i get the correct pagination of 1, 2, 3 – What am i doing wrong?

add_action( 'pre_get_posts', 'trr_query_offset', 1 );
function trr_query_offset( &$query ) {
    if ( ! ( $query->is_home() || is_main_query() ) ) {
        return;
    }

    $offset = -1;

    $ppp = get_option( 'posts_per_page' );

    if ( $query->is_paged ) {
        $page_offset = $offset + ( ( $query->query_vars['paged']-1 ) * $ppp );
        $query->set( 'offset', $page_offset );
    } else {
        $query->set( 'posts_per_page', $offset + $ppp );
    }
}

add_filter( 'found_posts', 'trr_adjust_offset_pagination', 1, 2 );
function trr_adjust_offset_pagination( $found_posts, $query ) {
    $offset = -1;

    if ( $query->is_home() && is_main_query() ) {
        return $found_posts - $offset;
    }
    return $found_posts;
}
``