2n-1+2n+1+2n+3=69
6n+3=69
6n=66
n=11
значит
21, 23 ,25
013, 015,031, 051, 053, 035
103, 105, 130, 150, 135, 153
301, 305, 310, 350, 351, 315
501, 503, 530, 510, 531, 513
24 числа.