145920

Appears in sequences

• Number of divisor chains of length n in which the first term is a divisor of n(n+1)/2 ("cyclic" divisor chains).at n=32A094098
• Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 310", based on the 5-celled von Neumann neighborhood.at n=17A287604
• Theta series of the 24-dimensional lattice of hyper-roots E_5(SU(3)).at n=5A288776
• Numbers k such that k and usigma(k) have the same set of prime divisors, where usigma(k) is the sum of unitary divisors of k (A034448).at n=34A329858