480249

Appears in sequences

• 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=11A095175
• Denominators in the fractional coefficients that form the partial quotients of the continued fraction representation of the inverse tangent of 1/x.at n=11A110256
• 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=5A110260
• Numbers k such that the representation of phi(k) is a cyclic permutation of that of k, in base 10.at n=15A113781
• Squares for which both the sum of the digits and the product of the digits are cubes.at n=23A117687
• Perfect squares in A133459; or perfect squares that are the sums of two nonzero pentagonal pyramidal numbers.at n=30A136359
• Squares that become a prime number when prefixed with a 5.at n=20A167720
• Squares that become prime numbers when prefixed with an 8.at n=28A167723
• The numbers n^2 as n runs through the numbers which are palindromes in base 2.at n=52A192775
• Number of n X 4 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=20A208138
• 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=12A239225
• Squares representable as k*m + k + m, where k >= m > 1 are squares.at n=34A256074
• Numbers n such that the product of n and the sum of the reciprocal of their anti-divisors is an integer.at n=29A272890
• Odd numbers k such that rad(k) divides sigma(k).at n=28A336554
• a(n) is the least number with exactly n divisors of the form 4*k+1.at n=22A364584
• a(n) is the least number with exactly n divisors of the form 4*k+3.at n=22A364585
• Odd squares k, multiples of 3 and non-multiples of 5, such that sigma(k)/k >= 5/3.at n=16A388016
• a(n) = denominator((2^n*(n!)^2/(1+2*n)!)^2).at n=5A392619