A Leyland number is an integer of the form
 |
with integers 
. The ordering 
avoids counting the same pair twice. The restriction
excludes the trivial representation
for every integer 
.
Under this strict convention, the values begin 8, 17, 32, 54, 57, 100, 145, 177, 320, 368, 512, 593, .... The OEIS sequence OEIS A076980
prepends 3 as an exceptional value. Every value with 
is at least 8, so 3 is not generated by the strict
definition.
When 
,
the value 
is a composite number. The prime
numbers of this form are called Leyland primes.
."