169728

Appears in sequences

• A unitary phi reciprocal amicable number: consider two different numbers r, s which satisfy the following equation for some integer k: uphi(r) = uphi(s) = (1/k) * r * s / (r-s); or equivalently, 1/uphi(r) = 1/uphi(s) = k * (1/s - 1/r); sequence gives r numbers.at n=22A080766
• a(n) = 13 + floor(Sum_{j=1..n-1} a(j)/3).at n=33A120157
• Number of n X 4 0..1 arrays avoiding 0 0 0 and 1 1 1 horizontally and 0 0 1 and 0 1 1 vertically.at n=24A208065
• Number of compositions of n in which the minimal multiplicity of parts equals 8.at n=20A244171
• Square array read by antidiagonals downwards: super Patalan numbers of order 4.at n=22A248325