91482563640
domain: N
Appears in sequences
- Expansion of (sqrt(1-4x^2) - sqrt(1-4x))/(2x).at n=22A000912
- Number of prime binary rooted trees with n external nodes.at n=21A035010
- Catalan numbers with even index (A000108(2*n), n >= 0): a(n) = binomial(4*n, 2*n)/(2*n+1).at n=11A048990
- a(n) = mu(n) * Catalan(n).at n=22A062627
- Carlitz-Riordan q-Catalan numbers (recurrence version) for q = -1.at n=45A090192
- a(1) = 1; a(n) = floor {(n+1)(n+2)(n+3)...(n+k)}/{(n-1)(n-2)(n-3)...(n-k)} for the least value of k.at n=22A092935
- Expansion of 1 + 2x/(1 + sqrt(1 - 4x^2)).at n=45A097331
- G.f. is 1 + x*c(x), where c(x) is the g.f. of the Catalan numbers (A000108).at n=23A120588
- Catalan numbers (A000108) interpolated with 0's.at n=44A126120
- The matrix-vector product A133080 * A000108.at n=22A133602
- Even Catalan numbers.at n=17A152670
- a(n) = (-1)^n*Catalan(n).at n=22A168491
- Catalan trisection: A000108(3*n+1), n>=0.at n=7A187358
- First terms of first rows of zigzag matrices as defined in A088961.at n=20A230585
- Catalan numbers C(n) such that sum of the factorials of digits of C(n) is semiprime.at n=6A242897
- G.f.: Sum_{n>=0} x^(n^2) * C(x^n)^n, where C(x) = 1 + x*C(x)^2 is the g.f. of the Catalan numbers (A000108).at n=23A299042
- Expansion of g.f.: Catalan(x)/Catalan(-x).at n=22A349648
- Expansion of g.f. A(x) satisfying A( A(x) - C(x) ) = x^2, where C(x) = x + C(x)^2 is the Catalan function (A000108).at n=22A373310
- Catalan numbersat n=22