54120
domain: N
Appears in sequences
- Heptagonal (or 7-gonal) pyramidal numbers: a(n) = n*(n+1)*(5*n-2)/6.at n=40A002413
- Coordination sequence for D_4 lattice.at n=15A007900
- Fibonacci sequence beginning 0, 8.at n=20A022091
- The binary encoding (as a rooted planar tree) of each rooted planar binary tree. See A057123 for illustration.at n=14A057122
- A014486-indices of symmetric binary trees.at n=35A083940
- Fourth partial sums of fourth powers (A000583).at n=7A101091
- a(n) = 4*n*(floor(n^2/2)+1). For n >= 3, this is the number of directed Hamiltonian paths on the n-prism graph.at n=30A124350
- Number of (directed) Hamiltonian paths in the n-Möbius ladder graph.at n=27A137883
- G.f. satisfies: A(x)^(1/2) = x + A(x) + A(A(x)) + A(A(A(x))) + A(A(A(A(x)))) +...at n=9A141201
- a(n) = A165641(n+1)/A165641(n).at n=39A165886
- a(n) = Fibonacci(n) * A004018(n) for n>=1 with a(0)=1, where A004018(n) is the number of ways of writing n as a sum of 2 squares.at n=20A205507
- Number of n-digit 7th powers.at n=36A216657
- Even heptagonal pyramidal numbers.at n=29A218325
- Numbers i such that Fibonacci(i) is divisible by i, i+1, i+2, and i+3.at n=19A298685
- Number of 11-regular partitions of n (no part is a multiple of 11).at n=43A328545
- a(n) = n * Clausen(n, 1) / Clausen(n, 0).at n=40A363395