28768

Appears in sequences

• a(n) = floor(n*(n-1)*(n-2)*(n-3)/30).at n=32A011940
• Numbers whose base-13 representation has exactly 5 runs.at n=23A043660
• Open 3-dimensional ball numbers (version 4): a(n) is the number of integer points (i,j,k) contained in an open ball of diameter n, centered at (1/2, 1/2, 1/2).at n=38A053596
• Reverse of largest prime factor of n = smallest prime factor of n+1; a(1)=1.at n=22A071393
• Triangle read by rows: coefficients d(n,k) of André polynomials D(x,n) = Sum_{k>0} d(n,k)*x^k.at n=28A094503
• Triangle read by rows: T(n,k) = (k+1)*T(n-1,k) + (n-k+1)*T(n,k-1).at n=24A096078
• Inverse Moebius transform of Fibonacci numbers 0, 1, 1, 2, 3, 5, 8, ...at n=23A108046
• Triangle read by rows: number of simsun n-permutations with k descents.at n=27A113897
• Denominator of sum of reciprocals of first n 5-simplex numbers A000389.at n=27A118432
• (1/8)*number of lattice points with odd indices in a cubic lattice inside a sphere around the origin with radius 2*n.at n=37A120884
• a(n) = 8*a(n-1) - 2*a(n-2), with a(0)=0, a(1)=1.at n=6A190975
• Practical numbers q with q + 2 and q^2 + 2 both practical.at n=16A294225
• Numbers k such that 397*2^k+1 is prime.at n=24A323043
• Nonunitary weird numbers: numbers that are nonunitary abundant but not nonunitary pseudoperfect.at n=4A327948
• Number of partitions of [n] such that the element sum of each block is odd.at n=11A369079
• a(1)=1; for n>1, a(n) = a(n-1) / k if there exists an unused positive integer k (choose the smallest) such that a(n) is a distinct positive integer; otherwise a(n) = a(n-1) * k if the same conditions apply.at n=38A371359