100530

Appears in sequences

• One half of the number of permutations of [n] such that the differences have 4 runs with the same signs.at n=5A000486
• Triangle T(n,k) = P(n,k)/2, n >= 2, 1 <= k < n, of one-half of number of permutations of 1..n such that the differences have k runs with the same signs.at n=39A008970
• Volume of elliptic cone (rounded down) with semi-minor axis = height = n and semi-major axis = 3*n/2.at n=39A228391