28305

Appears in sequences

• Expansion of Product_{m>=1} (1+q^m)^(-30).at n=4A022625
• Numbers m such that phi(m) = tau(m)^3.at n=16A068559
• Diagonal in array of n-gonal numbers A081422.at n=29A081438
• Numbers k such that k + sigma(k) + phi(k) is a square.at n=36A116009
• Elements of A065607 from primitive triples.at n=26A120693
• Hilltop maps: number of n X 3 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..2 n X 3 array.at n=4A218587
• T(n,k)=Hilltop maps: number of nXk binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..2 nXk array.at n=25A218592
• Hilltop maps: number of 5Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..2 5Xn array.at n=2A218596
• Number of partitions p of n such that the multiplicity of 2*min(p) is a part.at n=43A240496
• Numbers x such that the sum of all their cyclic permutations is equal to that of all cyclic permutations of sigma(x) and all cyclic permutations of Euler totient function phi(x).at n=37A247317
• Coordination sequence for (2,6,infinity) tiling of hyperbolic plane.at n=21A265070
• Square array read by antidiagonals: A(n,k) is the number of ordered solutions (x_1, x_2, ..., x_n) to equation phi(Product_{i=1..n} x_i) = k * Sum_{i=1..n} phi(x_i), or -1 if there are infinitely many solutions, n >= 1, k >= 1.at n=75A336710