simple for loop

HEllo guys,

I'm trying to take my output into a txt file but something is wrong.

Code:H=$(head -n1 SAMPLE.txt) ## = 19990

for ((i = $H ; i <= 19999 ; i++))
do
echo $i > FILL2.txt
donefor some reason it gives me only 19999 in FILL2.txt
while the output of echo $i is:
19990
19991
19992
19993
19994
and so on until 19999

what is wrong? I don't understand.