201684

Appears in sequences

• Triangle of coefficients in expansion of (2 + 7*x)^n.at n=26A013623
• Triangle whose (i,j)-th entry is binomial(i,j)*7^(i-j)*2^j.at n=22A038268
• Number of endofunctions on n labeled points constructed from k rooted trees.at n=22A066324
• Numbers of the form (7^i)*(12^j), with i, j >= 0.at n=21A108238
• The sum of the degree of each root node over all rooted labeled trees on n nodes.at n=7A206855
• Triangular array read by rows: T(n,k) is the number of functions f:{1,2,...,n} -> {1,2,...,n} that have exactly k nonrecurrent elements; n>=1, 0<=k<=n-1.at n=26A219694
• Triangular array read by rows: T(n, k) is the number of rooted forests on {1, 2, ..., n} in which one tree has been specially designated that contain exactly k trees; n >= 1, 1 <= k <= n.at n=22A225465
• Numbers whose square is both a sum and a difference of two positive cubes.at n=30A230716
• Terms of a particular integer decomposition of N^N.at n=30A243203
• Base-7 complementary numbers: n equals the product of the 7 complement (7-d) of its base-7 digits d.at n=9A298977
• Generated by Marf-Low rule 173.at n=43A328086
• Number of indecomposable closed walks of length 2n along the edges of a cube based at a vertex.at n=7A328778
• Terms of A301517 that are not exponentially odd numbers (A268335).at n=17A335989
• Triangular array read by rows. T(n,k) is the number of closed walks of length 2n along the edges of a cube based at vertex v that return to v exactly k times, n>=0, 0<=k<=n.at n=29A336667
• Table T(n,k) = phi(phi(prime(n)^k)), n >= 1, k >= 0, read by upwards antidiagonals, where phi = A000010.at n=62A380500
• Nonprimes k such that sopfr(k) = rad(k), where sopfr(k) is sum of the prime factors of k (counting multiplicity), and rad(k) is the product of its distinct prime factors.at n=11A386916
• a(n) is the smallest composite k such that radical(k) = sopfr(k) = A350352(n).at n=1A391316