41409225

Appears in sequences

• Successive denominators of Wallis's approximation to Pi/2 (reduced).at n=15A001902
• Coefficients of Legendre polynomials.at n=8A002462
• Squares of numbers in array formed from odd elements to the right of middle of rows of Pascal triangle that are not 1.at n=18A014760
• Squares of numbers in array formed from odd elements to the right of middle of rows of Pascal triangle.at n=32A014761
• a(n) = binomial(n, floor(n/2))^2 = A001405(n)^2.at n=15A018224
• Numerators of coefficients of EllipticK/Pi.at n=8A038534
• Duplicate of A038534.at n=8A048056
• a(0) = 1; for n > 0, binomial(2n-1, n-1)^2.at n=8A060150
• Numerators of ratio of sides of n-th triple of rectangles of unit area sum around a triangle.at n=16A094083
• Denominator of b(n) given by b(1) = 1, b(2) = 2; for n >= 3, b(n) = (-1)^n (2n-1) ((n-2)!!)^2/((n-1)!!)^2, where n!! is the double factorial A006882.at n=15A095175
• Denominators in the fractional coefficients that form the partial quotients of the continued fraction representation of the inverse tangent of 1/x.at n=15A110256
• Denominators in the coefficients that form the even-indexed partial quotients of the continued fraction representation of the inverse tangent of 1/x.at n=7A110260
• Triangle T(n,m) = (A006882(2*n + 1))^2 / ( A006882(2*m+1) * A006882(2*n-2*m+1) ).at n=31A153512
• Triangle T(n,m) = (A006882(2*n + 1))^2 / ( A006882(2*m+1) * A006882(2*n-2*m+1) ).at n=32A153512
• Denominators of the column sums of the BG2 matrix.at n=7A161736
• Norm of coefficients in g.f. C(x) that satisfies: C(x) = 1 + x/C(I*x).at n=32A193384
• Denominator of 2n/v(n)^2, where v(1) = 0, v(2) = 1, and v(n) = v(n-1)/(n-2) + v(n-2) for n >= 3. (Limit of 2n/v(n)^2 is Pi.)at n=15A239225
• Denominator of 2n/v(n)^2, where v(1) = 0, v(2) = 1, and v(n) = v(n-1)/(n-2) + v(n-2) for n >= 3. (Limit of 2n/v(n)^2 is Pi.)at n=16A239225
• a(n) = binomial(n, floor((n-1)/2))^2.at n=15A378060
• a(n) = binomial(n - 1, ceiling(n/2)) * binomial(n - 1, ceiling(n/2) - 1).at n=16A378070