New Year's Countdown Day 15: Anti-magical Diagonals
Define a heterosquare to be a square grid containing consecutive positive integers starting from 1 such that the sums of the integers in each row, column, and long diagonal are all different. Furthermore, define an anti-magic square to be a heterosquare whose sums form a consecutive sequence of integers.
If there exists a \(15 \times 15\) anti-magic square, then there are \(n\) possible values \(d_1, d_2, \dots, d_n\) for the sum of its two diagonal sums. Find the value of \(n \displaystyle \sum_{i = 1}^n d_i.\)
\(\)
Note: A diagonal sum is the sum of the numbers along a long diagonal of the square. For example, the two diagonal sums of the following square are \(1 + 5 + 9 = 15\) and \(3 + 5 + 7 = 15:\)
\[
\begin{array}{|c|c|c|}
\hline 1 & 2 & 3 \\
\hline 4 & 5 & 6 \\
\hline 7 & 8 & 9 \\
\hline
\end{array}
\]
This problem is related to Open Problem #2 of the Brilliant.org Open Problems Group.
This problem is part of the set New Year's Countdown 2017.
by
Steven Yuan