26880

Appears in sequences

• Number of 3-line Latin rectangles.at n=3A000536
• Negated coefficients of Chebyshev T polynomials: [x^n](-T(n+6, x)), n >= 0.at n=8A001794
• Theta series of laminated lattice LAMBDA_15.at n=3A023938
• Theta series of A2[hole]^4.at n=40A033690
• a(n) = (2*n+8)!!/8!!, related to A000165 (even double factorials).at n=4A051582
• There are exactly n integer-sided triangles of area a(n).at n=25A051586
• a(n) = 2^(n-1) * n! * Catalan(n-1) for n > 0 with a(0) = 0.at n=5A052714
• Expansion of e.g.f. x^4*exp(x)^2.at n=8A052796
• Number of primitive (period n) step cyclic shifted sequences using a maximum of four different symbols.at n=9A056421
• 2-enumeration of 2n X 2n half-turn symmetric alternating-sign matrices.at n=4A057170
• Numbers k such that cototient(k) is a square and sets a new record for squares.at n=36A063753
• Least prime signature numbers that are not a Jordan-Polya number.at n=34A064783
• Maximal number of divisors of any n-digit number.at n=14A066150
• a(n) = Z(S_m; sigma[1](n), sigma[2](n),..., sigma[m](n)) where Z(S_m; x_1,x_2,...,x_m) is the cycle index of the symmetric group S_m and sigma[k](n) is the sum of k-th powers of divisors of n; m=3.at n=19A068020
• Smallest integer that can be expressed as the sum of consecutive odd numbers in exactly n ways.at n=27A068314
• Coefficients of (-x^(2n-6)) in Chebyshev polynomial of degree 2n.at n=4A068548
• 11-almost primes (generalization of semiprimes).at n=29A069272
• Triangular array T(n,k) read by rows, giving number of labeled free trees such that the root is smaller than all its children, with respect to the number n of vertices and to the degree k of the root.at n=32A071210
• Numbers k such that A074037(k) = A002034(k).at n=28A074055
• Let P(k,X) = Product_{i=1..2*k} (X-1/cos(Pi*(2*i-1)/(4*k)) ) which is a polynomial with integer coefficients. Sequence gives array of coefficients for P(k,X).at n=56A075615