73122

Appears in sequences

• a(1) = a(2) = a(3) = 1; for n>3, a(n) = a(n-1) + a(n-2) + a(n-3) iff n-1 is prime, otherwise a(n) = a(n-1) + 1.at n=40A113057
• Number of (n+1) X (3+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=3A250872
• T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=18A250877
• Number of (4+1) X (n+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=2A250881
• Number of set partitions of [n] into exactly five blocks such that all odd elements are in blocks with an odd index and all even elements are in blocks with an even index.at n=11A274869
• Triangle read by rows: T(n, k) is the number of permutations of size n that require exactly k iterations of the pop-stack sorting map to reach the identity, for n >= 1, 0 <= k <= n-1.at n=41A359413