223197

Appears in sequences

• Quasi-Carmichael numbers to base -3: squarefree composites n such that for every prime p that divides n, p+3 divides n+3.at n=20A029563
• Number of -4..4 arrays x(i) of n+1 elements i=1..n+1 with x(i)+x(j), x(i+1)+x(j+1), -(x(i)+x(j+1)), and -(x(i+1)+x(j)) having one, three or four distinct values for every i<=n and j<=n.at n=4A211692