51128

Appears in sequences

• a(n) = n*(n+2)*(2*n-1)/3. Also, row sums of triangle A131422.at n=41A131423
• A129065 with v=n instead of v=1: recursive polynomial coefficient triangle.at n=45A136453
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 1), (1, 0, -1), (1, 0, 1), (1, 1, 0)}.at n=8A150753
• a(n) = 4*(n + 1)*(n + 2)*(4*n + 3)/3.at n=20A267522
• Rectangular array A read by upward antidiagonals in which the entry A(n,k) in row k and column n gives the number of families of symmetric radially generated monohedral tilings of the disk (each tiling contains 2*(2*n+1)*k congruent tiles), k >= 1, n >= 1.at n=16A273090
• a(n) = A273059(4n+3).at n=39A275919
• Number of monohedral disk tilings of type C^t_{5,n}.at n=4A296362
• T(n, k) = A343277(n)*[x^k] p(n, x) where p(n, x) = (1/(n+1))*Sum_{k=0..n} (-1)^k*E1(n, k)*x^(n - k) / binomial(n, k), and E1(n, k) are the Eulerian numbers A123125. Triangle read by rows, for 0 <= k <= n.at n=52A342321
• a(n) is equal to the sum of the factorials of the digits of a(n-1), with a(1) = 0; each time a duplicated term appears, we replace it with the smallest integer not yet in the sequence and iterate.at n=46A351328
• a(n) = Sum_{k=0..floor(n/4)} 2^(n-4*k) * binomial(2*n-6*k+1,2*k+1).at n=10A387696