19621

Appears in sequences

• Gaps of 2 in sequence A038593 (upper terms).at n=18A038644
• Number of primes == 7 (mod 10) less than 10^n.at n=5A073507
• Antidiagonal sums of square array A082025.at n=29A082190
• n sets a new record in A094830.at n=11A094878
• Numbers n such that n and its digit reversal R(n) both are difference of positive cubes.at n=24A109879
• a(n) = smallest composite (odd) number greater than a(n-1) such that a(n)+2n is the first prime after a(n).at n=19A189118
• Triangle T(n, k) = Number of non-equivalent (mod D_3) ways to arrange k indistinguishable points on a triangular grid of side n so that no three points are collinear. Triangle read by rows.at n=47A234350
• Centered cubohemioctahedral numbers: a(n) = 2*n^3+9*n^2+n+1.at n=20A274973
• a(n) is the number of n-celled treelike polyominoes in the {4,5} tessellation of the hyperbolic plane.at n=9A390195