A054388 Denominators of coefficients of 1/2^(2n+1) in Newton's series for Pi.

1, 3, 5, 28, 72, 704, 1664, 2560, 17408, 311296, 688128, 3014656, 6553600, 56623104, 121634816, 520093696, 369098752, 7516192768, 79456894976, 111669149696, 704374636544, 5909874999296, 824633720832, 51677046505472