248509

Properties

Appears in sequences

• Number of permutations of {1,2,...,n} containing exactly 4 occurrences of the 132 pattern.at n=6A138162
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n-1) + b(n-2) + b(n-3), where a(0) = 1, a(1) = 3, a(2) = 5, b(0) = 2, b(1) = 4, b(2) = 6, and (a(n)) and (b(n)) are increasing complementary sequences.at n=21A295357
• a(n) = Sum_{k=0 .. n} Sum_{j=0 .. k} tan(j*Pi/(1 + 2*k))^(2*(n - k)). Antidiagonal sums of A377657.at n=7A377658
• Prime numbersat n=21921