<?php

$alpha = range('A', 'Z');  
for( $i = 0; $i < 26; $i++ ) {   
  for( $k = 26; $k > $i ; $k-- ){  
    echo $alpha[$i];  
    }  
    echo "\n";  
}  

result AAAAAAAAAAAAAAAAAAAAAAAAAA BBBBBBBBBBBBBBBBBBBBBBBBB CCCCCCCCCCCCCCCCCCCCCCCC DDDDDDDDDDDDDDDDDDDDDDD EEEEEEEEEEEEEEEEEEEEEE FFFFFFFFFFFFFFFFFFFFF GGGGGGGGGGGGGGGGGGGG HHHHHHHHHHHHHHHHHHH IIIIIIIIIIIIIIIIII JJJJJJJJJJJJJJJJJ KKKKKKKKKKKKKKKK LLLLLLLLLLLLLLL MMMMMMMMMMMMMM NNNNNNNNNNNNN OOOOOOOOOOOO PPPPPPPPPPP QQQQQQQQQQ RRRRRRRRR SSSSSSSS TTTTTTT UUUUUU VVVVV WWWW XXX YY Z