ABC2 ($a-1)*$a^$b-1 | ($a-1)*$a^$b+1 | ($a+1)*$a^$b-1 | ($a+1)*$a^$b+1 | $a^$b-($a-1) | $a^$b+($a-1) | $a^$b-($a+1) | $a^$b+($a+1)
a: from 2 to 64
b: from 1 to 25000