25804

Appears in sequences

• a(n) = 2*a(n-1) - a(n-2) - a(n-4) with a(0) = a(1) = 0, a(2) = 1, a(3) = 2.at n=30A014292
• McKay-Thompson series of class 12H for Monster.at n=14A058486
• Numbers k such that (k+3)^(k+2) mod (k+1) = k.at n=5A064935
• Numbers n such that 2*10^n + 7*R_n - 4 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=11A102958
• Sums of least knight's moves from (0,0) to points in the square lattice [-n,n]x[-n,n].at n=25A183047
• McKay-Thompson series of class 12H for the Monster group with a(0) = 4.at n=14A187091
• McKay-Thompson series of class 12H for the Monster group with a(0) = 5.at n=14A187198
• Expansion of (1/q) * ((chi(q^3) * chi(-q^6)) / (chi(q) * chi(-q^2)))^4 in powers of q where chi() is a Ramanujan theta function.at n=14A193522
• Expansion of (1/q) * chi(-q) * chi(-q^3) * chi(-q^6)^4 / chi(q)^4 in powers of q where chi() is a Ramanujan theta function.at n=14A193557
• G.f.: imaginary part of 1/(1 - i*x - i*x^2) where i=sqrt(-1).at n=30A201838
• Number of compositions (ordered partitions) of n into at most 6 squarefree parts.at n=29A347783
• a(n) is the number of trivial braids on 3 strands with 2*n crossings.at n=5A354602
• Number of rooted trees with n nodes, at most half of which are leaves.at n=13A358584