170820

Appears in sequences

• Number of primitive (aperiodic, or Lyndon) asymmetric rhythm cycles: ones having no nontrivial shift automorphism.at n=13A006575
• Numbers k such that the sum of unitary divisors of k^2 is a square.at n=29A064498
• Triangular numbers for which the sum of the digits equals the sum of the digits of the next triangular number.at n=28A117511
• a(n) = 3*a(n-1) - a(n-3) + 3*a(n-4), with initial values 0,0,0,1.at n=14A133405
• Number of (w,x,y,z) with all terms in {1,...,n} and 3w>=x+y+z+n.at n=31A212250
• Number of strong dichotomy patterns in Z/2nZ, i.e., bicolor patterns of Z/2nZ with respect to the action of Aff(Z/2nZ) with trivial isotropy group.at n=21A360624
• Number of unordered pairs of distinct strict integer partitions of n.at n=35A366132
• Triangular numbers such that the three numbers before it and the three numbers after it are squarefree.at n=16A374393