3931200

Appears in sequences

• Expansion of Eisenstein series E_4(q) (alternate convention E_2(q)); theta series of E_8 lattice.at n=24A004009
• a(n) = ceiling(n!/d(n!)).at n=12A055981
• Numbers k such that sigma(k) - usigma(k) > 3k.at n=24A063875
• Product of the first n (semiprimes - 1).at n=6A112228
• 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=27A115387
• a(1)=1. a(n) = a(n-1)*(b(n-1)+1), where {b(k)} is the concatenated list of the positive divisors of the terms of {a(k)}.at n=12A129643
• Numbers that can be written as (a^2-1)(b^2-1) in three or more distinct ways.at n=21A134856
• Denominator of Bernoulli(2n)/(2n!).at n=6A255506
• a(n) = denominator of (1/n^3)*(-1/(n+1) + 16/(n+2) + 3/(4*(2*n+1)) - 81/(4*(2*n+3))), term of a BBP-type series representation of zeta(3) by V. Adamchik and S. Wagon.at n=11A256324
• Highly composite numbers of class 3 (see comment in A275239).at n=37A275241
• Coefficients of a family of orthogonal polynomials. Triangle read by rows, T(n, k) for 0 <= k <= n.at n=39A322944
• Triangle read by rows: T(n,k) is the number of achiral colorings of the facets of a regular n-dimensional orthotope using exactly k colors. Row n has 2n columns.at n=51A325011
• Obverse convolution (1)**A000201; see Comments.at n=8A374860