806400

Appears in sequences

• Theta series of the coset of the E_7 lattice in its dual.at n=31A005931
• a(n) = n!*(n+3)! / 3!.at n=5A010792
• Numbers m such that uphi(sigma(m)) = 2m, where the unitary phi function (A047994) is defined by: if x = p1^r1*p2^r2*p3^r3*... then uphi(x) = (p1^r1 - 1)*(p2^r2 - 1)*(p3^r3 - 1)*...at n=16A030165
• Number of identity bracelets with n labeled beads of 5 colors.at n=5A032340
• Value of phi in arithmetic progression of at least 5 terms having the same value of phi in A050515.at n=24A050517
• Value of phi in arithmetic progression of at least 5 terms having the same value of phi in A050515.at n=26A050517
• E.g.f. 1/(1-2x-x^4).at n=7A052667
• Triangle of coefficients of x^2 in the Neumann polynomials.at n=32A057869
• Triangle T(n,k) of number of minimal 3-covers of a labeled n-set that cover k points of that set uniquely (k=3,..,n).at n=23A057964
• Sum of unitary divisors of central binomial coefficient C(n, floor(n/2)).at n=20A064140
• Number of adjacent pairs of form (odd,odd) among all permutations of {1,2,...,n}.at n=8A077611
• Number of adjacent pairs of form (even,odd) among all permutations of {1,2,...,n}. Also, number of adjacent pairs of form (odd,even).at n=8A077613
• Phi(m)*sigma(m), where m is the product of exactly two primes that differ by 2, where phi=A000010, sigma=A000203.at n=4A094949
• Sum of the non-unitary divisors of A064115(n) (or of 1+A064115(n)).at n=15A103846
• a(n) = sigma(A067651(n)).at n=22A107816
• A triangular sequence based on expansion of the rational polynomial of A023054 as a Sheffer sequence: p(x,t)=Exp[x*t]*(1 - t^5)/((1 - t)*(1 - t^2)^2*(1 - t^3)).at n=36A138186
• Triangle T(n, k) = H(n, k+1) - 2*H(n, k) - H(n, k-1), where H(n, k) = A060821(n+3, k), read by rows.at n=24A140873
• Number of reduced words of length n in Coxeter group on 16 generators S_i with relations (S_i)^2 = (S_i S_j)^4 = I.at n=5A163092
• a(n) = A091137(n+1)/(n+1).at n=8A174727
• Triangle read by rows: the coefficient [t^n x^k] of n!*(n+2)! *exp(x*t) *(t*(1-2*exp(t))-2*exp(t)) / (2*(1-exp(t))), in row n, k=0..n+1.at n=47A176989