136278

Appears in sequences

• Number of 0..n arrays of length 5 with each element differing from at least one neighbor by something other than 1, starting with 0.at n=18A221543
• a(n) = Sum_{k=1..n} phi(k)*phi(k+1)*phi(k+2), where phi(k) = A000010(k) is Euler's totient function.at n=39A335131