26911

Appears in sequences

• sech(sin(tan(x)))=1-1/2!*x^2+1/4!*x^4+47/6!*x^6+897/8!*x^8...at n=5A012018
• a(n) = 841*n - 1.at n=31A158402
• a(n) = 32*n^2 - 1.at n=28A158563
• a(n) = n^3 - 3n^2 + 3.at n=31A177058
• Number of 0..4 arrays of length n with each element differing from at least one neighbor by something other than 1.at n=6A221569
• T(n,k)=Number of 0..k arrays of length n with each element differing from at least one neighbor by something other than 1.at n=51A221573
• Number of 0..n arrays of length 7 with each element differing from at least one neighbor by something other than 1.at n=3A221577
• a(n) = Sum_{i=1..n, j=1..n, gcd(i,j)=1} i.at n=43A333297