between its fellow books, tucked it under his arm and descended the ladder. Once he was down, he opened the book, balancing it on his forearms.
Muko, who was standing nearest, edged closer and peered over the professor's shoulder to see what he was looking at. He had opened the book at the chapter entitled 'Collection of perfect numbers'. There was a column on the left in which were the numbers 6, 28, 496, 8128. There was another number next to these but it was so long that Muko didn't have time to read it.
Now the professor turned to a chapter called 'Collection of sociable numbers', then quickly went back a couple of pages till he got to the chapter 'Collection of amicable numbers'.
“Here it is,” he grunted with suppressed excitement.
Muko could see that there were numbers arranged in pairs on the page. The first pair was 220, 284, and then 1184, 1210. There were more pairs. The old man scanned the rows repeating 998104 and 1043096 over and over. He went to the end of the third page where there was the pair 947835, 1125765.
“Yes. The next one's mine. Thank goodness for that,” he
sighed. He was beaming with delight.