1204140

Appears in sequences

• Number of perfect matchings on an n X n L-shaped graph.at n=15A079472
• Row sums of an unsigned characteristic triangle for the Fibonacci numbers.at n=15A110035
• Number of derangements of [n] avoiding the patterns 123, 132 and 213.at n=30A114215
• Denominators a(n) of Pythagorean approximations b(n)/a(n) to 1/2.at n=14A195547
• Numbers n such that n^3 = x*y*z where 2 <= x <= y <= z , n^3+1 = (x-1)*(y+1)*(z+1).at n=7A240836
• a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = 1, a(1) = 2, a(2) = 3, a(3) = 4.at n=29A293411
• a(n) = a(n-1) + a(n-3) + a(n-4), where a(0) = 0, a(1) = 0, a(2) = 0, a(3) = 2.at n=32A295680
• a(n) = A000045(n)*A000045(n+1) mod A000032(n).at n=31A357553