43778

Appears in sequences

• Numbers k such that k^2 + 1 is composite and phi(k^2 + 1) == 0 (mod k).at n=39A067519
• Number of (n+2)X(n+2) 0..3 arrays with every 3X3 subblock row and column sum 3 or 6 and every diagonal and antidiagonal sum not 3 or 6.at n=2A251771
• Number of (n+2)X(3+2) 0..3 arrays with every 3X3 subblock row and column sum 3 or 6 and every diagonal and antidiagonal sum not 3 or 6.at n=2A251774
• T(n,k)=Number of (n+2)X(k+2) 0..3 arrays with every 3X3 subblock row and column sum 3 or 6 and every diagonal and antidiagonal sum not 3 or 6.at n=12A251779
• The number of length-n permutations avoiding the patterns 1234, 1324 and 2143.at n=10A263790
• a(n) = Sum_k k*A333275(n,k).at n=15A333277
• Numbers m such that m^2 + p^2 = k^2, with p > 0, where p = A007954(m) = the product of digits of m.at n=10A334558