A046573 First denominator and then numerator of the central elements of the 1/4-Pascal triangle (by row).

1, 1, 4, 1, 2, 5, 2, 19, 1, 35, 2, 259, 1, 483, 1, 1815, 1, 6864, 2, 52195, 1, 99671, 1, 382109, 1, 1469650, 1, 5668327, 1, 21915550, 1, 84913470, 1, 329624730, 2, 2563431075, 1, 4991324415, 1, 19463777025, 1, 75992317170, 1, 297026449005, 1