21160

Appears in sequences

• a(n) = dot_product(n,n-1,...2,1)*(5,6,...,n,1,2,3,4).at n=41A026060
• Decimal part of a(n)^(1/3) starts with a 'nine digits' anagram.at n=7A034278
• Numbers that have exactly six prime factors counted with multiplicity (A046306) whose digit reversal is different and also has 6 prime factors (with multiplicity).at n=28A109026
• Number of (n+2) X 8 0..1 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..1 introduced in row major order.at n=16A204379
• Positive integers, c, such that there are more than two solutions to the equation a^2 + b^3 = c^4, with a, b > 0.at n=19A242381
• Coordination sequence for (3,6,8) tiling of hyperbolic plane.at n=16A265077
• Numbers that are values of the totient function (A002202) but not of the reduced totient function (A002174).at n=9A270265
• Characteristic polynomials of Jacobi coordinates. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=30A298854
• Characteristic polynomials of Jacobi coordinates. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=33A298854
• a(n)/n! is the expected number of left-to-right maxima in the lexicographical or colexicographical ordering of all the 2-subsets of [n] under a random permutation of [n], when the 2-subsets hold the worst order of ranks.at n=6A308729
• First differences of A345882.at n=12A347685
• a(n) = (n - 1) * Sum_{k=2..n} A000010(k).at n=40A385682
• a(n) is the number of concave n-celled polyominoes in the {4,5} tessellation of the hyperbolic plane.at n=11A390199