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A233835
a(n) = 8*binomial(7*n + 8, n)/(7*n + 8).
12
1, 8, 84, 1008, 13090, 179088, 2542512, 37106784, 553270671, 8391423040, 129058047580, 2008018827360, 31550226597162, 499892684834368, 7978140653296800, 128138773298754240, 2069603881026760323, 33593111381834512200, 547698081896206040800, 8965330544164089648000, 147285313888568167177866
OFFSET
0,2
COMMENTS
Fuss-Catalan sequence is a(n,p,r) = r*binomial(n*p + r, n)/(n*p + r); this is the case p = 7, r = 8.
LINKS
Jean-Christophe Aval, Multivariate Fuss-Catalan Numbers, Discrete Math., Vol. 308, No. 20 (2008), 4660-4669; arXiv preprint, arXiv:0711.0906 [math.CO], 2007.
Thomas A. Dowling, Catalan Numbers, Chapter 7 of Applications of discrete mathematics, John G. Michaels and Kenneth H. Rosen (eds.), McGraw-Hill, New York, 1991. [Wayback Machine link]
Wojciech Mlotkowski, Fuss-Catalan Numbers in Noncommutative Probability, Docum. Math. 15 (2010), 939-955.
FORMULA
G.f. satisfies: A(x) = (1 + x*A(x)^(p/r))^r, where p = 7, r = 8.
From Peter Bala, Oct 16 2015: (Start)
O.g.f.: A(x) = (1/x) * series reversion (x*C(-x)^8), where C(x) = (1 - sqrt(1 - 4*x))/(2*x) is the o.g.f. for the Catalan numbers A000108. See cross-references for other Fuss-Catalan sequences with o.g.f. (1/x) * series reversion (x*C(-x)^k), k = 3 through 11.
A(x)^(1/8) is the o.g.f. for A002296. (End)
a(n) ~ 7^(7*n+15/2)/ (2^(6*n+6) * 3^(6*n+17/2) * n^(3/2) * sqrt(Pi)). - Amiram Eldar, Sep 16 2025
MATHEMATICA
Table[8 Binomial[7 n + 8, n]/(7 n + 8), {n, 0, 30}]
PROG
(PARI) a(n) = 8*binomial(7*n+8, n)/(7*n+8);
(PARI) {a(n)=local(B=1); for(i=0, n, B=(1+x*B^(7/8))^8+x*O(x^n)); polcoeff(B, n)}
(Magma) [8*Binomial(7*n+8, n)/(7*n+8): n in [0..30]];
CROSSREFS
Cf. A000245 (k = 3), A006629 (k = 4), A196678 (k = 5), A233668 (k = 6), A233743 (k = 7), A234467 (k = 9), A232265 (k = 10), A229963 (k = 11).
Sequence in context: A166483 A048665 A005797 * A380712 A300993 A052659
KEYWORD
nonn,easy
AUTHOR
Tim Fulford, Dec 16 2013
STATUS
approved