42774

Appears in sequences

• a(n) = H(n)*n!/(floor(n/2))!, where H(n) = Sum_{k=1..n} 1/k, the n-th harmonic number.at n=9A124078
• a(n) = H(2n+1)*(2n+1)!/n!, where H(n) = Sum_{k=1..n} 1/k, the n-th harmonic number.at n=4A124079
• Number of planar n X n X n binary triangular grids with mirror symmetry about one altitude with every one adjacent to exactly 2 other ones.at n=11A153987
• Number T(n, k) of ways to place k points on an n X n X n triangular grid so that no pair of them has distance sqrt(3). Triangle read by rows.at n=44A244500
• Integers k such that A014841(k) = A014841(k+1).at n=15A356961