81396

Appears in sequences

• MacMahon's generalized sum of divisors function.at n=31A002128
• Numbers whose base-5 representation has exactly 8 runs.at n=13A043608
• Maximal number of 165432 patterns in a permutation of 1,2,...,n.at n=24A100356
• Triangle read by rows, where the g.f. satisfies A(x, y) = 1 + x*A(x, y)^2 + x*y*A(x, y)^3.at n=33A104978
• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1),U=(1,2), or d=(1,-1) and have k peaks of the form Ud.at n=30A108426
• Triangle read by rows: T(n,k) is number of paths from (0,0) to (3n,0) that stay in the first quadrant (but may touch the horizontal axis), consisting of steps u=(2,1), U=(1,2), or d=(1,-1) and have k down steps (d).at n=61A108429
• a(n) = (n-1)*n*(n+1)*(n+2)*(2*n+1)/40.at n=17A112851
• Smallest positive number of "triangular" shuffles of n(n+1)/2 cards needed to restore them to their original order.at n=18A122158
• A triangle of coefficients: T(n,m) = (2*n + 2*m + 3)! / (2*(2*m + 1)!*(2*n + 1)!).at n=23A143083
• Triangle T(n,m) read by rows: The number of m-Schroeder paths of order n with 2 diagonal steps.at n=16A173622
• a(n) = (n-3)*(n-2)*(n-1)*n*(n+1)/30.at n=20A210569
• Number of 2 X 2 matrices having all terms in {-n,...,0,...,n} and determinant > n.at n=9A211151
• a(n) = 3*binomial(n+1,6).at n=13A253943
• Number of orbits of Aut(Z^7) as function of the infinity norm n of the representative lattice point of the orbit, when the cardinality of the orbit is equal to 322560.at n=19A266387
• Numbers k such that binomial(k^2,k) == 0 (mod k^3).at n=12A371474
• a(n) = [(x*y)^n] Product_{k>=1} (1 - x^k - y^k)^k.at n=20A381011
• 2nd diagonal (from right) in A104978.at n=5A383450
• a(n) = Sum_{k=0..floor(n/3)} binomial(n+k-1,k) * binomial(k,n-3*k).at n=16A389290
• a(n) = Sum_{k=0..floor(n/2)} binomial(k+3,4*n-8*k+3).at n=35A390040
• a(n) = Sum_{k=0..floor(2*n/7)} binomial(2*k+1,2*n-7*k).at n=38A392456