6

Part of 2004 Switzerland - Final Round

Problems(1)

1^n + 2^n + 3^n + 4^n ending in k zeros

Source: Switzerland - 2004 Swiss MO Final Round p6

k

for which there exists a natural number n such that

1^n + 2^n + 3^n + 4^n

k

zeros at the end.

number theorylast digits