(1329 ) 
N= 7172 422 
2 <i -pi= 1435 
ae 
3294 
1439 
41 
6174 
1443 
5 
mint. 
10509 
1449 
51 
13409 
1453 
5 
t 
17774 
1459 
61 
20694 
1463 
5 
7 
25089 
1469 
71 
20029 
1473 
5 
7 
32454 
1479 
Sl 
35414 
1483 
5 
fi 
39869 
1489 
91 
42849 — 207? =b? 
So we have 
As soon as 62 = 207? has been 
found, the value of a’ can be 
calculated in different manners. 
In the first place by adding A to 
the result 42849 we find 
a? = 556516 = 746°. 
Secondly one can remark, that 
from 1435 unto 1491 (the first 
and last of the added numbers) 
a number of 
1491—1435 
5 +1, i.e. 29 
odd numbers have been added; 
this gives 
a= 717+ 29 = 746. 
Thirdly — and this method is 
the shortest — one can observe 
that by continuing the operation 
the number 1493 had to be added 
and that this number is equal to 
2a +1; so 
1493—1 
2 
= or 
N = 7462 — 2072 = 953 X 539. 
After two additions the factor 539 appears to be equal to 30?—19?, 
