-7264

Appears in sequences

• a(1) = 1; a(n) = sigma(n) - sigma(n-1)* a(n-1) if n > 1.at n=6A079897
• Matrix inverse square-root of triangle A105615.at n=39A105620
• Triangle T(n, k) = k^4 - n^4 + 2*k*n*(1 - k^2*n^2), read by rows.at n=18A123963