46816

Appears in sequences

• Numbers k such that phi(k) = Sum_{d|k} core(d) where core(x) is the squarefree part of x (A007913).at n=18A074786
• Lower triangular matrix T, read by rows, that shifts left one column under the matrix square of T, with T(n,0)=T(n,1) for n>0 and T(n,n)=1 for n>=0.at n=41A098539
• Triangle read by rows: T(n,k) is number of leaves at level k in all noncrossing rooted trees on n+1 nodes.at n=30A101372
• Smaller side in (a,a+1,a+1)-integer triangle with integer area.at n=3A103975
• Triangle read by rows: T(n,m) is the number of cyclic permutations of [n] in which m of successive numbers add to a prime. 0<=m<=n, read by rows n>=0.at n=59A132178
• Sums of the products of n consecutive pairs of numbers.at n=32A135036
• Numbers n such that sigma(n) = 7*phi(n).at n=11A136540
• Number of ordered triples (w,x,y) with all terms in {1,...,n} and w^2>2x^2+2y^2.at n=36A211633
• Triangular array read by rows: row n shows the coefficients of the polynomial u(n) = c(0) + c(1)*x + ... + c(n)*x^(n) which is the numerator of the n-th convergent of the continued fraction [k, k, k, ... ], where k = x + 1/2.at n=48A231730
• a(n) = number of triangles that can be formed from the points of a 3 X n grid.at n=22A262402
• Numbers n such that there exist three nonnegative integers a,b, and c satisfying n=a*b and (a^2+b^2)/(1+a*b) = c^2.at n=18A268198
• Triangle T(n, k) = [x^n] (n + k + x)!/(k + x)! for 0 <= k <= n, read by rows.at n=41A325137
• Number of unlabeled multigraphs with loops allowed and n edges covering three vertices.at n=28A327728
• Triangle read by rows. The partition transform of A355488, which are the alternating row sums of the number of permutations of [n] with k components (A059438).at n=47A357078
• G.f. A(x) satisfies A(x) = 1 + x + x*(1 + x)^4*A(x)^2.at n=7A366238
• Number of ways to place k nonattacking anassas on an n X n chess board. Triangle T(n,k) read by rows.at n=32A378561