It looks like seq for integers bigger than 2^64 sometimes generate wrong 
results. There are few examples of wrong output I have found:


$ seq 18446744073709551617 inf | head -3

18446744073709551616
18446744073709551617
18446744073709551618





$  seq 10000000000000000000000000000 inf | head -3


9999999999999999999731564544
9999999999999999999731564545
9999999999999999999731564546





$  seq -1000000000000000000000000 0 | head -3


-1000000000000000000000000
-1000000000000000000000000
-1000000000000000000000000




It is similar to bug #75994 which reports the same issue but only for "-w"
option.