1260230400

Appears in sequences

• a(n) = (2^n + 2) a(n-1) (kissing number of Barnes-Wall lattice in dimension 2^n).at n=7A006088
• Theta series of Barnes-Wall lattice in 128 dimensions.at n=4A100004
• a(1) = 2; for n>1, a(n)=SENSigma(a(n-1)), where SENSigma(m) = (-1)^((Sum_i r_i)+Omega(m))*Sum_{d|m} (-1)^((Sum_j Max(r_j))+Omega(d))*d = Product_i (Sum_{1<=s_i<=r_i} p_i^s_i)+(-1)^(r_i+1) if m=Product_i p_i^r_i, d=Product_j p_j^r_j, p_j^max(r_j) is the largest power of p_j dividing m.at n=25A125141
• a(1)=1; for n>1: a(n) = sum of all subsets of (a(1),..,a(n-1)).at n=8A126391
• Numerator of the harmonic mean of the first n composite numbers.at n=23A250132