$emails =array() // This is an array of 4600 emails of which i am generating a batch range for each 1000 emails
$batch= ceil(count($emails)/1000); // i am getting how many batches i need to get
$lowe=0; //lower range for initialization
$upper=$lowe+999; //upper range for initialization
for ($i=0; $i < $batch; $i++) {
if ($i!=0) {
$lowe=$upper+1;
$upper= $upper+$lowe;
}
$ss[]=['lower'=>$lowe,'upper'=>$upper];
}
return ($ss); // response is [{"lower":0,"upper":999},{"lower":1000,"upper":1999},{"lower":2000,**"upper":3999},{"lower":4000,"upper":7999},{"lower":8000,"upper":15999}]**
// yet i expect [{"lower":0,"upper":999},{"lower":1000,"upper":1999},{"lower":2000,"upper":2999},{"lower":3000,"upper":3999},{"lower":4000,"upper":4999}]