304668

Appears in sequences

• 9 + 8*a(n) appears in a congruence which determines representative parallel primitive binary quadratic forms for discriminant 9*m(n)^2 - 4 and representation -m(n)^2, where m(n) = A002559(n) (Markoff numbers).at n=10A327344
• Indices k at which record low values of the ratio A046530(k)/k occur.at n=43A330695