61880

Appears in sequences

• a(n) = 5*binomial(n, 6).at n=17A000910
• Iteration of unitary-sigma function: a(1) = 2, a(n) = usigma(a(n-1)).at n=25A059460
• a(n) = n*(n^2 - 1)*(n+2)*(2*n^5 + 14*n^4 + 49*n^3 + 91*n^2 + 90*n + 18)/324.at n=5A064203
• a(n) = lcm{1, ..., 2n} / binomial(2n, n).at n=17A068550
• Triangle of C(n+1,k)*C(2*n-3*k,n-3*k)/(n+1) by rows.at n=38A073187
• Triangle read by rows: T(n,k) = binomial(2n+1, n-k)*Fibonacci(2k+1), 0 <= k <= n.at n=38A103245
• 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=31A104978
• 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=32A108426
• 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=59A108429
• a(n) = (prime(n)^5 - prime(n))/6.at n=5A138427
• a(n) = lcm{1,2,...,n} / swinging_factorial(n) = A003418(n) / A056040(n).at n=34A180000
• Coefficient of x^n in the expansion of (1+x^3+x^4)^n.at n=17A192442
• 8-quantum transitions in systems of N >= 8 spin 1/2 particles, in columns by combination indices.at n=29A213350
• a(n) = 2*(2*n+1)*A000538(n) - 4*A000330(n)^2.at n=7A259317
• a(n) = lcm{1,2,...,n} / binomial(n,floor(n/2)).at n=34A263673
• a(n) = 10*binomial(n+4, 5).at n=13A266732
• Number of nX7 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.at n=1A280672
• T(n,k)=Number of nXk 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.at n=29A280673
• Number of 2 X n 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.at n=6A280674
• Triangle read by rows: T(n,k) = binomial(2*n+1, 2*k+1)*binomial(2*n-2*k, n-k)/(n+1-k) for 0 <= k <= n.at n=41A281000