Solutions - Georg Mohr-Konkurrencen

There are kghij(n) = 8 g−1 · 8 h−g−1 · 8 i−h−1 · 8 j−i−1 · 9 n−j such numbers a.
Obviously, kghij(n) ≡ 1 (mod 8) for g = 1, h = 2, i = 3, j = 4, and
kghij(n) ≡ 0 (mod 8) in all other cases. Since k(n) is obtained by summing
up the values of kghij(n) over all possible choicecs of g, h, i, j , the
remainder we are looking for is 1.
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