999855

Appears in sequences

• Nonnegative k such that 7*k^2 + 7*k + 1 is a square.at n=5A105040
• Define a(1)=0, a(2)=0, a(3)=15, a(4)=111 then a(n) = 254*a(n-2) - a(n-4) + 126 also sequence such that 7*a(n)*(a(n) + 1) + 1 = a square.at n=6A105051