81080

Appears in sequences

• Number of nonempty subsets of {1,2,...,n} in which exactly 3/4 of the elements are <= (n-2)/3.at n=33A048020
• Number of nonempty subsets of {1,2,...,n} in which exactly 3/4 of the elements are <= (n-3)/3.at n=33A048031
• Triangle read by rows giving the coefficients of formulas generating each variety of S1(n,k) (unsigned Stirling numbers of first kind). The p-th row (p>=1) contains T(i,p) for i=1 to 2*p, where T(i,p) satisfies Sum_{i=1..2*p} T(i,p) * C(n,i).at n=32A094216
• Numbers k such that both k and k+1 are abundant.at n=19A096399
• Numbers k such that both sigma(k) >= 2*k-1 and sigma(k+1) >= 2*(k+1)-1.at n=21A103289
• Coefficients of expansion polynomial:p(x,t)=Exp[ -t^2* x](1 - t)^(-x)/x.at n=48A174893
• Numbers k such that both k and k+1 are Zumkeller numbers (A083207).at n=17A328327