393120

Appears in sequences

• Number of 4 X n Latin rectangles in which the first row is in order.at n=2A003170
• a(n) = Product_{i=2..n} sigma(i)/bigomega(i).at n=7A066987
• a(1) = a(2) = 1; a(n) = sigma(a(n-1)+a(n-2)).at n=14A069143
• A Jacobsthal Fibonacci product: a(n) = (2^n + 2*(-1)^n)*Fibonacci(n-1)/3.at n=13A093044
• Magic products of 5 X 5 multiplicative magic squares.at n=3A111031
• Triangle of the numbers of unique-valued sequences of all lengths (from 1 to 2n-1) consisting of unit matrices (="matrix units") of order n.at n=32A114595
• a(1) = 1. For n >= 2, a(n) = sum of the two (not necessarily distinct) earlier terms, a(j) and a(k), which maximizes d(a(j)+a(k)), where d(m) is the number of positive divisors of m. a(n) = the minimum (a(j)+a(k)) if more than one such sum has the maximum number of divisors.at n=23A115387
• Sigma(A033631(n)) {sigma is the sum of divisors function A000203}.at n=36A115619
• Number of n X n real symmetric (0,1)-matrices having maximal determinant (=A119002(n)).at n=8A119004
• Amicable triples. Sequence gives sigma values: A125490(n) + A125491(n) + A125492(n).at n=25A137231
• Amicable triples. Sequence gives sigma values: A125490(n) + A125491(n) + A125492(n).at n=26A137231
• Scalar product of Atkin polynomial A_n(j) with itself.at n=1A145228
• Triangle T(n, k) = 2*n*binomial(2*n-k, k)*(n-k)!/(2*n-k), with T(0, 0) = 2, read by rows.at n=48A156995
• The number of different 4-colorings for the vertices of all triangulated planar polygons on a base with n vertices if the colors of two adjacent boundary vertices are fixed.at n=11A174395
• Conjecturally, numbers j for which f(m) > f(j) for all m > j, where f(k) = H(k) + exp(H(k))*log(H(k)) - sigma(k).at n=30A176679
• Numbers which are the area of exactly three Pythagorean triangles.at n=31A177021
• Triangle of coefficients arising from an expansion of Integral( exp(exp(exp(x))), dx).at n=42A188881
• Molecular topological indices of the triangular graphs.at n=13A192849
• Position of records in A067513.at n=35A202727
• a(n) = (n-3)*(n-2)*(n-1)*n*(n+1)/30.at n=27A210569