20328

Appears in sequences

• Number of possible rook moves on an n X n chessboard.at n=21A035006
• Numbers k such that 165*2^k-1 is prime.at n=48A050834
• Number of permutations of n letters where exactly 5 change position.at n=10A060836
• a(n) = 11*n^2 + 22*n.at n=41A067705
• Expansion of (1-x)^(-1)/(1+x-2*x^2-x^3).at n=18A077897
• a(n) = (5/6)*n^3+(5/2)*n^2+(8/3)*n.at n=28A092185
• Products x*y*z arising from A102495.at n=32A102509
• Products x*y*z arising from A102505.at n=24A102793
• Permutations with exactly 6 fixed points.at n=5A129136
• Partial sums of A032598.at n=15A129330
• Antidiagonal sums of the triangle A120070.at n=41A143785
• Triangular array of generalized Narayana numbers: T(n, k) = 4*binomial(n+1, k+3)*binomial(n+1, k-1)/(n+1).at n=38A145598
• Triangular array of generalized Narayana numbers: T(n, k) = 4*binomial(n+1, k+3)*binomial(n+1, k-1)/(n+1).at n=42A145598
• Greatest number m such that the fractional part of (10/9)^A153694(n) <= 1/m.at n=9A153698
• a(n) = 1728*n - 408.at n=11A157266
• Numbers m such that m = Sum_{i=x..y} i = (10^k)*y + x, where 0 <= x < y, 0 <= x < 10^k for some positive integers k.at n=4A186076
• Highest scoring cribbage hand with n cards.at n=19A195676
• Integer areas A of the integer-sided triangles such that the product of the inradius and the circumradius is a square.at n=27A232329
• Number of comparisons required to sort all permutations of [n] by MTF sort.at n=6A280970
• Ordered perimeters p of primitive Pythagorean triangles no side of which is squarefree.at n=35A329392