46920

Appears in sequences

• The binary encoding (as a rooted planar tree) of each rooted planar binary tree. See A057123 for illustration.at n=10A057122
• Records in A104883.at n=29A104884
• a(n) = binomial(n,4) - binomial(floor(n/2),4) - binomial(ceiling(n/2),4).at n=35A111385
• G.f.: A(x) = exp( Sum_{n>=1} sigma(n)^4 * x^n/n ).at n=6A205797
• E.g.f. satisfies: A(x) = exp( A(x) * Series_Reversion( Integral A(x) dx ) ).at n=7A233337
• Let x(0)x(1)x(2)... x(q) denote the decimal expansion of n. Sequence lists the numbers n such that the suffix of decimal expansion x(2)... x(q) is the p-th divisor of n where p is the prefix of decimal expansion x(0)x(1).at n=11A234315
• Number of orbits of size n in vertex graph of Lucas cube Lambda_n.at n=43A250114
• Least k formed by the concatenation of two numbers n and d such that d is the n-th divisor of k, or 0 if no such k exists.at n=45A257491
• Numbers m such that the concatenation of k and the k-th divisor of m is equal to m for some k.at n=21A258738
• a(n) = Sum_{k=0..n} 2^(n-k) * binomial(n-1,n-k) * binomial(2*k,k).at n=7A360317