28678

Appears in sequences

• Closed 3-dimensional ball numbers (version 2): a(n)= number of integer points (i,j,k) contained in a closed ball of diameter n, centered at (1/2,0,0).at n=38A053593
• Open 3-dimensional ball numbers (version 2): a(n) is the number of integer points (i,j,k) contained in an open ball of diameter n, centered at (1/2,0,0).at n=38A053594
• Areas of a sequence of right-angled figures described below.at n=22A058195
• Numbers k such that k and k^2 use only the digits 2, 4, 6, 7 and 8.at n=26A137101
• Generalized Markoff numbers: largest of 7-tuple of positive numbers a, b, c, d, e, f, g satisfying the Markoff(7) equation a^2+b^2+c^2+d^2+e^2+f^2+g^2 = 2abcdefg.at n=30A227210
• y-values in the solution to x^2 - 13y^2 = 108.at n=16A228206
• a(n) = 3*a(n-1) - 2*a(n-2) - a(n-3) + a(n-4), where a(1) = 1, a(2) = 3, a(3) = 5, a(4) = 8.at n=21A232896
• Exponents m such that the decimal expansion of 4^m exhibits its first zero from the right later than any previous exponent.at n=20A239009
• Numbers n such that sigma(n) is a Fibonacci number.at n=21A272412
• a(n) is the smallest nonnegative integer m such that the integer part of tan(m) is equal to n.at n=35A327788
• Indices of the Sylvester primes (A375543) in the primes (A000040).at n=37A375545
• Numbers k such that tau(k) and sigma(k) are both Fibonacci numbers.at n=8A390231
• Number of edges in a complete bipartite graph where the vertices in the two parts are placed on opposite sides of a parabola at integer y coordinates y = 1, 2, ...n.at n=15A392444