218790

Appears in sequences

• Coefficients of Legendre polynomials.at n=7A001801
• a(n) = (2n+1)!/n!^2.at n=8A002457
• Triangle of coefficients of Legendre polynomials P_n (x).at n=39A008316
• Expansion of (1-4*x)^(17/2).at n=8A020929
• First numerator and then denominator of central elements of Leibniz's Harmonic Triangle.at n=17A046212
• Array T(i,j) = binomial(-1/2-i,j)*(-4)^j, i,j >= 0 read by antidiagonals going down.at n=46A046521
• a(n) = LCM_{k=0..n} (2^k + 1).at n=6A051844
• Swinging factorial, a(n) = 2^(n-(n mod 2))*Product_{k=1..n} k^((-1)^(k+1)).at n=17A056040
• a(n) = n!/(k!)^2, where k is the largest number such that (k!)^2 divides n!.at n=16A056042
• Expansion of (1+9*x)/(1-x)^11.at n=8A056114
• a(n) = (8*n+9)*C(n+8,8)/9.at n=9A056122
• T(n,k) = binomial(n,k)*binomial(n+k,k), 0 <= k <= n, triangle read by rows.at n=53A063007
• Irregular triangle of the Fibonacci polynomials of A011973 multiplied diagonally by the Catalan numbers.at n=43A068763
• First integer reached when starting with n/floor(log_2(n)) and iterating the map x -> x*ceiling(x) A075107(n) times, or -1 if no integer is ever reached.at n=15A075108
• First integer reached when starting with n/floor(sqrt(n)) and iterating the map x -> x*ceiling(x) A075120(n) times, or -1 if no integer is ever reached.at n=16A075121
• Square of Narayana triangle A001263: View A001263 as a lower triangular matrix. Then the square of that matrix is also lower triangular. Sequence gives this lower triangle, read by rows.at n=46A095801
• a(n) = n * binomial(n-1, floor((n-1)/2)) = n * max_{i=0..n} binomial(n-1, i).at n=17A100071
• Triangle read by rows: T(n,k) is the number of lattice paths from (0,0) to (n,n) using steps E=(1,0), N=(0,1) and D=(1,1) (i.e., bilateral Schroeder paths), having k D=(1,1) steps.at n=46A104684
• Riordan array (1/((1-4*x)*c(x)),x*c(x)/sqrt(1-4*x)), c(x) the g.f. of A000108.at n=46A113955
• Triangle, read by rows, defined by T(n,k) = A000108(n-k)*A001147(k)*C(n,2*k), for k=0..[n/2], n>=0, where A000108 is the Catalan numbers and A001147 is the double factorials.at n=31A125080