- ABCDEFGF = AE + BE + CE + DE + EE + FE + GE + FE, where each of A and E is nonzero, and:
- ABCDEFGF does not contain the digit 1, and:
- Reading from left to right, odd digits appear in descending order of magnitude, but the nonzero even digits appear in ascending order of magnitude, in ABCDEFGF.