263965

Appears in sequences

• Number of (n+2)X(3+2) 0..1 arrays with each 3X3 subblock having clockwise perimeter pattern 00000001 00000101 or 00001011.at n=15A261550
• a(n) = Sum_{i=1..n} Sum_{j=1..n} Sum_{k=1..n} phi(i*j*k) / phi(j*k).at n=27A372663