229653domain: NAppears in sequencesNumbers n such that sigma(n)/phi(n) = 25/9, where sigma = A000203, phi = A000010.at n=6A165630Principal diagonal of the convolution array A213551.at n=16A213552Number of length n+1 0..3 arrays with at most one downstep in every n consecutive neighbor pairs.at n=14A258731