117572

Appears in sequences

• a(n) = (1/(4n-1))*C(4n,2n).at n=6A024491
• Dirichlet convolution of Catalan numbers (1,2,5,14...) with themselves.at n=10A034717
• a(n) is the difference between maximal and central squarefree kernel numbers dividing values of {binomial(n,k)} or A001405(n), respectively.at n=20A048682
• Partial sums of A051879.at n=12A050405
• Third diagonal of array in A059347.at n=21A059348
• Expansion of (1 + x*C)*C, where C = (1 - (1 - 4*x)^(1/2))/(2*x) is the g.f. for Catalan numbers, A000108.at n=11A068875
• Number of fixed points in range [A014137(n-1)..A014138(n-1)] of permutation A089864.at n=24A089408
• Denominators of row sums in triangle described in A093412.at n=20A093419
• Denominator of -3*n + 2*(1+n)*HarmonicNumber(n).at n=21A096620
• Self-convolution of repeated Catalan numbers.at n=21A104722
• Denominators of values T(m,m) of urn game described in A108885 and A108886.at n=12A108884
• The 3rd Witt transform of A000292.at n=13A147621
• Denominator of the Harary number for the path graph P_n.at n=21A160049
• Trisection of A000984 (central binomial coefficients): binomial(2(3n+2),3n+2)/3!, n>=0.at n=3A187365
• Composition of Catalan and Fibonacci numbers.at n=67A189675
• Given n and a constant C, define a sequence b(m) by the recurrence in the comments; a(n) = smallest positive integer C such that for some prime p the denominators of all b(m) are powers of p (conjectured).at n=10A216814
• The number of boundary twigs for complete binary twigs. A twig is a vertex with one edge on the boundary and only one other descendant.at n=10A228403
• a(n) = A241477(n, n).at n=24A241543
• Let s denote the sum of the abundant numbers in the aliquot parts of x. Sequence lists numbers x such that sigma(s) = usigma(x), where usigma(x) is the sum of the unitary divisors of x (A034448).at n=24A258135
• Number of rooted asymmetrical polyenoids of type U_n* having n edges.at n=11A262543