I'm calculating BRK repurchased 23,744.4 class A shares equivalent as follows:
On Feb 13, 2020, BRK had 700,395 Class A and 1,385,994,959 Class B shares outstanding, adding up to a total of 1,624,393 Class A equivalent shares. See https://www.berkshirehathaway.com/2019ar/2019ar.pdf.
On July 7, 2020, Buffett owned 248,734 Class A and 10,188 Class B shares, adding up to a total of 248,740.792 Class A equivalent shares. His total economic share in BRK was 15.54%. This puts total Class A equivalent shares of BRK to be 248,740.792/0.1554 = 1,600,648.597. See https://www.sec.gov/Archives/edgar/data/315090/000119312520189490/d936378dsc13da.htm
1,624,393 - 1,600,648.597 = 23,744.4 class A equivalent shares repurchased
There were 1,620,023 class A equivalent according to the 1st quarter 10-Q. About 19,300 this quarter.