304336

Appears in sequences

• a(n) = Sum_{i=0..n} T(i,n-i) where T is given by A047020.at n=20A047021
• Determinant of n X n matrix of form : [1 2 1 0 0 0 0 0 0 0 / 2 1 2 1 0 0 0 0 0 0 / 1 2 1 2 1 0 0 0 0 0 / 0 1 2 1 2 1 0 0 0 0 / 0 0 1 2 1 2 1 0 0 0 / 0 0 0 1 2 1 2 1 0 0 / 0 0 0 0 1 2 1 2 1 0 / 0 0 0 0 0 1 2 1 2 1 / 0 0 0 0 0 0 1 2 1 2 / 0 0 0 0 0 0 0 1 2 1].at n=20A071534
• Number of ways to place 2 nonattacking zebras on an n X n board.at n=27A172137
• Greater of a pair of amicable numbers k < m such that s(k) = m and s(m) = k, where s(k) = A162296(k) - k is the sum of aliquot divisors of k that have a square factor.at n=7A357496