27956

Appears in sequences

• Numerator of the average height of a binary search tree on n elements.at n=11A195582
• Number of -n..n arrays x(0..3) of 4 elements with zero sum and nonzero second differences.at n=16A200554
• Least positive integer k such that prime(prime(k)), prime(prime(k*n)), prime(p) and prime(q) form a 4-term arithmetic progression for some pair of primes p and q.at n=3A261462
• Number of achiral triangular polyominoes with 6n cells and sixfold rotational symmetry.at n=22A364684