181632

Appears in sequences

• Arctanh(tan(x)+log(x+1)) = 2*x - 1/2!*x^2 + 20/3!*x^3 - 54/4!*x^4 + 1188/5!*x^5 + ...at n=7A012932
• Number of permutations pi in S_n such that maj pi and maj pi^(-1) have the same parity where maj is the major index. Equivalently, the number of pi such that maj pi and inv pi have the same parity where inv is the inversion number.at n=9A113247
• Numbers x,y,z such that UnitarySigma(x) = UnitarySigma(y) = UnitarySigma(z) = 3*(x*y*z)^(1/2)/(- x^(1/2) + 8*y^(1/2) - 5*z^(1/2)), z<=y<=x; sequence gives x.at n=9A144672
• Numbers x,y,z such that UnitarySigma(x) = UnitarySigma(y) = UnitarySigma(z) = 3*(x*y*z)^(1/2)/(- x^(1/2) + 8*y^(1/2) - 5*z^(1/2)), z<=y<=x; sequence gives y.at n=9A144673
• Numbers x,y,z such that UnitarySigma(x) = UnitarySigma(y) = UnitarySigma(z) = 3*(x*y*z)^(1/2)/(- x^(1/2) + 8*y^(1/2) - 5*z^(1/2)), z<=y<=x; sequence gives z.at n=9A144674
• Numbers m such that A034448(m) = 3m/2, where A034448 = unitary sigma = sum of divisors d with gcd(d,m/d)=1.at n=9A145681
• Number of distinct classes of permutations of length n under reversal and complement to n+1.at n=9A275527
• 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=37A329858
• Number of involutions (plus identity) in a fixed Sylow 2-subgroup of the symmetric group of degree n.at n=26A332759
• Number of involutions (plus identity) in a fixed Sylow 2-subgroup of the symmetric group of degree n.at n=27A332759
• Number of involutions (plus identity) in a fixed Sylow 2-subgroup of the symmetric group of degree 2n.at n=13A332868