18963

Appears in sequences

• P_n'(3), where P_n is n-th Legendre polynomial.at n=5A002695
• Divisors of 2^42 - 1.at n=36A003547
• Number of paraffins.at n=41A005997
• dot_product(n,n-1,...2,1)*(7,8,...,n,1,2,3,4,5,6).at n=36A026066
• Numbers k that divide 5^k + 4^k.at n=35A045590
• a(n) = n^2*(2*n+1).at n=21A099721
• Triangle read by rows: T(n,k) is the number of bicolored Dyck paths of semilength n and having k peaks of the form ud (0 <= k <= n). A bicolored Dyck path is a Dyck path in which each up-step is of two kinds: u and U.at n=30A114608
• Expansion of g.f.: -x*(1 - 2*x + 6*x^2 - 2*x^3 + x^4)/((1-x)^3*(1+x)^4).at n=41A122576
• a(n) = n*floor(n/2)^2.at n=43A122656
• a(6n+k) = 3a(6n+k-1)-3a(6n+k-2)+2a(6n+k-3), k = 0, 1, 3, 4, 5; a(6n+2) = 3a(6n+1)-3a(6n). a(0) = a(1) = 0, a(2) = 1.at n=17A132658
• The discriminant of the characteristic polynomial of the O+ and O- submatrix for spin 3 of the nuclear electric quadrupole Hamiltonian is a perfect square for these values.at n=9A136331
• Antidiagonal sums of the triangle A120070.at n=40A143785
• Number of zero-sum -n..n arrays of 5 elements with first through third differences also in -n..n.at n=12A202513
• Number of n X 4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=13A207020
• Number of (w,x,y,z) with all terms in {0,...,n}, w even, and x = y + z.at n=41A212760
• a(n) is the denominator of polygamma(2n+1, 1) / Pi^(2n+2).at n=20A255007
• Hemi-imperfect numbers: numbers such that the denominator of k/A206369(k) is equal to 2.at n=10A295236
• Number of ways to select 4 numbers from the set of the first n natural numbers avoiding 3-term arithmetic progressions.at n=25A300760
• Numbers that are the sum of 4 nonzero 4th powers in more than one way.at n=39A309763
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of 1/(1 - 2*k*x + ((k-2)*x)^2)^(3/2).at n=41A331514