@ @RW@ @óïbÿa@‡ÉÜa@ú†bjà@ @
400 . 9 ×10 = 90
[Gauss 2011] ( )
3 21
.( 3 2 1) 3 AB
A,B ∈ {1,2, 3}
ABC .3×3 = 9
. 3 × 3 × 3 = 27 A, B,C ∈ {1, 2, 3}
3 + 9 + 27 = 39 [Gauss 2009] ( )
. 400
101
. 50 + 51 3 + 98 2 + 99 1 + 100
40
18 . 50
12 [Gauss 2009] ( )
15
.