17681020

Appears in sequences

• First numerator and then denominator of the central elements of the 1/3-Pascal triangle (by row).at n=26A046543
• First denominator and then numerator of the central elements of the 1/3-Pascal triangle (by row).at n=27A046544
• Distinct numbers in writing first numerator and then denominator of the central elements of the 1/3-Pascal triangle (by row).at n=13A046545
• a(n) = C(n)*(7*n + 1) where C(n) = Catalan numbers (A000108).at n=12A050477