23873

Properties

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has period 63.at n=29A020402
• Primes of form n^2 + n + 3.at n=18A027753
• Primes of the form k(k+1)/2+2 (i.e., two more than a triangular number).at n=41A055472
• Primes p equal to the sum of two successive sexy primes + 1 such that p + 6 is also prime.at n=33A104043
• a(n) = a(n-1)+a(n-2)-a(n-3)+a(n-5), n>7.at n=30A107287
• Number of acute triangles, distinct up to congruence, on an n X n grid (or geoboard).at n=25A190021
• Primes of the form 2k^2 + k + 2.at n=20A249606
• a(1)=2; thereafter, a(n) is the smallest prime not yet used which is compatible with the condition that a(n) is a quadratic residue modulo a(k) for the next n indices k = n+1, n+2, ..., 2n.at n=21A249782
• Number of nX3 0..1 arrays with every element unequal to 0, 1, 3, 4 or 6 king-move adjacent elements, with upper left element zero.at n=13A304539
• Number of equivalence classes of convex lattice polygons of genus n, restricting the count to those polygons that are interior to another polygon.at n=29A322344
• Prime numbersat n=2655