1767263189

Appears in sequences

• Catalan numbers - 1.at n=17A001453
• a(n) = Sum_{k|n} mu(k)*Catalan(n/k) (mu = Moebius function A008683).at n=18A002996
• a(n) = C(n)-1+0^n where C(n) = A000108(n).at n=19A141364