29280

Appears in sequences

• Glaisher's function U(n).at n=14A002612
• (-1)sigma perfect numbers: (-1)sigma(a) = m*a for some integer m, where if a = Product p(i)^r(i) then (-1)sigma(a) = Product_{i} (-1 + Sum_{s=1..r(i)} p(i)^s).at n=4A034094
• First element r of (-1)sigma sociable triple (r,s,t): s=(-1)sigma(r), t=(-1)sigma(s), r=(-1)sigma(t), where if x=Product p(i)^r(i), then (-1)sigma(x)=Product(-1+(Sum p(i)^s(i), s(i)=1 to r(i))).at n=24A049057
• (1+3^n)*n!.at n=5A052573
• First differences of A069474, successive differences of (n+1)^6-n^6.at n=7A069475
• Strongly refactorable numbers: numbers n such that if n is divisible by d, it is divisible by the number of divisors of d.at n=34A141586
• Number of permutations of floor(i*7/4), i=0..n-1, with all sums of 4 adjacent terms unique.at n=7A152340
• Triangle T(n, k) = [x^k](p(x, n, q)) where p(x,n,q) = Product_{j=1..n} (x + q^j) + Product_{j=1..n} (x*q^j + 1), p(x, 0, q) = 1, and q = 3, read by rows.at n=11A173049
• Triangle T(n, k) = [x^k](p(x, n, q)) where p(x,n,q) = Product_{j=1..n} (x + q^j) + Product_{j=1..n} (x*q^j + 1), p(x, 0, q) = 1, and q = 3, read by rows.at n=13A173049
• Numbers in A075728 which are not one less than some prime.at n=27A179232
• Number of fixed poly-[4.6.12]-tiles (holes allowed) with n cells (division into triangles is significant).at n=10A197464
• a(n) = 4*n^3 + 5*n^2 + 2*n + 1.at n=19A204674
• Triangle T(n,k), n>=3, 3<=k<=n, read by rows. Number of ways to make n selections without replacement from a circular array of n unlabeled cells (ignoring rotations and reflection), such that the first selection of a cell adjacent to previously selected cells occurs on the k-th selection.at n=30A249796
• Central nonzero values of A231599.at n=17A269298
• a(n) is the least k that is a multiple of A071395(n) (the n-th primitive abundant number) for which A003961(k) is abundant.at n=23A337469
• The number of compositions of n using elements from the set {1,3,5,7,8}.at n=23A349840
• Expansion of Sum_{0<i<j<k<l<m} q^(2*(i+j+k+l+m)-5)/( (1-q^(2*i-1))*(1-q^(2*j-1))*(1-q^(2*k-1))*(1-q^(2*l-1))*(1-q^(2*m-1)) )^2.at n=27A365667
• Number of polyforms with n cells on the faces of a disdyakis triacontahedron up to rotation.at n=13A383497
• Cluster series for percolation on the cells of the Cairo tiling.at n=12A390623