502500

Appears in sequences

• Number of periodic palindromes using exactly four different symbols.at n=17A056490
• Numbers k such that k and k^2 use only the digits 0, 2, 5 and 6.at n=48A136911
• The triangle T_2(n, m), where T_2(n, m) is the number of surjective multi-valued functions from {1, 1, 2, 3, ..., n-1} to {1, 2, 3, ..., m} by rows (n >= 1, 1 <= m <= n).at n=48A172106