18893

Appears in sequences

• Discriminants of real quadratic fields with class number 1 and related continued fraction period length of 18.at n=56A050967
• Coefficients in the expansion of C^3/B^4, in Watson's notation of page 118.at n=11A160527
• a(n) = A001209(n) + 1.at n=34A196069
• Number of length 4 1..(n+1) arrays with every leading partial sum divisible by 2, 3, 5, 7 or 11.at n=13A254951
• G.f. = b(2)*b(4)*b(6)/(x^8+x^7-x^3-x^2-x+1), where b(k) = (1-x^k)/(1-x).at n=14A266375
• The growth series for the affine Coxeter (or Weyl) group [3,3,5] (or H_4).at n=36A266783
• Number of parts in all partitions of n with largest multiplicity six.at n=30A320376
• Number of nondecreasing Motzkin paths of length n.at n=13A322325
• a(n) is the number of 5 element sets of distinct integer-sided trapezoids whose base angles are 60 degrees that fill an equilateral triangular grid of side n units formed by directly binary space partitioning 3-trapezoid sets without forming 4-trapezoid sets.at n=37A391203