okay so let's say i put £1000 into a bank that has interest of 1%, the value that is inside of the bank increases by 1% on the exact day and time i originally signed up with the bank every year. the bank does not care what i do with the money, if i put in £400 into the bank a minute before the value increases, that £400 will count as value that has increased. so if i leave £1000 into this bank for slightly less than a year then i put £400 into it a minute before the value increases by 1%, £1400 will increase by 1% meaning that my value in the bank will be £1414 after the increase.

my question is this: if i put £400 into the bank every year before the increase of 1%, is there a formula for the amount i will have in the bank after n amount of years (increases of 1%)