See which triplets of candidates were most frequent in the WPSE moderator election

vote-groups.php

<?php
$ballots = array(
array(1, 2, 3),
array(2, 4, 1),
array(5, 1, 4),
array(4, 2, 5),
array(1, 2, 4),
array(5, 4, 2),
array(6, 4, 5),
array(4, 1, 5),
array(5, 6, 4),
array(2, 3, 4),
array(4, 5, 2),
array(1, 4, 2),
array(4, 6, 2),
array(4, 2, 5),
array(4, 2, 6),
array(4, 5, 3),
array(1, 2, 5),
array(4, 5, 1),
array(5, 3, 2),
array(2, 5, 4),
array(4, 5, 1),
array(4, 1, 2),
array(4, 1, 3),
array(2, 1, 4),
array(4, 2, 5),
array(2, 4, 1),
array(4, 2, 1),
array(4, 2, 1),
array(4, 2, 1),
array(1, 5, 4),
array(5, 2, 3),
array(5, 2, 3),
array(4, 5, 1),
array(2, 4, 1),
array(4, 2, 3),
array(2, 3, 1),
array(5, 1, 4),
array(4, 2, 1),
array(4, 2, 5),
array(2, 4, 1),
array(4, 3, 1),
array(2, 1, 4),
array(6, 2, 5),
array(4, 2, 5),
array(4, 3, 1),
array(5, 2, 3),
array(3, 2, 1),
array(2, 5, 4),
array(1, 5, 2),
array(5, 1, 2),
array(4, 2, 1),
array(1, 2, 4),
array(4, 1, 2),
array(6, 4, 5),
array(6, 2, 1),
array(3, 2, 4),
array(4, 3, 1),
array(3, 6, 5),
array(4, 2, 3),
);

$voteGroups = array();
foreach ( $ballots as $ballot ) {
    sort( $ballot );
    $voteGroups[] = implode( '', $ballot );
}

$voteGroupCounts = array_count_values( $voteGroups );
asort( $voteGroupCounts );
foreach ( $voteGroupCounts as $voteGroup => $count ) {
    printf( "%s: %d\n", $voteGroup, $count );
}

Output:

256: 1
126: 1
356: 1
345: 1
246: 2
125: 3
456: 3
123: 3
134: 4
235: 4
234: 4
145: 7
245: 9
124: 16