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A000344 5*binomial(2n,n-2)/(n+3).
(Formerly M3904 N1602)
+0
27
1, 5, 20, 75, 275, 1001, 3640, 13260, 48450, 177650, 653752, 2414425, 8947575, 33266625, 124062000, 463991880, 1739969550, 6541168950, 24647883000, 93078189750, 352207870014, 1335293573130, 5071418015120, 19293438101000, 73514652074500, 280531912316292 (list; graph; listen)
OFFSET

2,2

COMMENT

a(n-3) = number of n-th generation vertices in the tree of sequences with unit increase labeled by 4 (cf. Zoran Sunik reference) - Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 07 2003

Number of lattice paths from (0,0) to (n,n) with steps E=(1,0) and N=(0,1) which touch but do not cross the line x-y=2 Example: For n=3 there are the 5 paths EENENN, EENNEN, EENNNE, ENEENN, NEEENN - Herbert Kociemba (kociemba(AT)t-online.de), May 24 2004

Number of standard tableaux of shape (n+2,n-2). - Emeric Deutsch (deutsch(AT)duke.poly.edu), May 30 2004

REFERENCES

Paul Barry, A Catalan Transform and Related Transformations on Integer Sequences, Journal of Integer Sequences, Vol. 8 (2005), Article 05.4.5.

V. E. Hoggatt, Jr. and M. Bicknell, Catalan and related sequences arising from inverses of Pascal's triangle matrices, Fib. Quart., 14 (1976), 395-405.

A. Papoulis, A new method of inversion of the Laplace transform, Quart. Applied Math. 14 (1956), 405ff.

J. Riordan, The distribution of crossings of chords joining pairs of 2n points on a circle, Math. Comp., 29 (1975), 215-222.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Zoran Sunik, Self describing sequences and the Catalan family tree, Elect. J. Combin., 10 (No. 1, 2003).

LINKS

R. K. Guy, Catwalks, Sandsteps and Pascal Pyramids, J. Integer Seqs., Vol. 3 (2000), #00.1.6

FORMULA

Integral representation as n-th moment of a function on [0, 4], in Maple notation: a(n)=int(x^n*((1/2)/Pi*x^(3/2)*(x^2-3*x+1)*(4-x)^(1/2)), x=0..4), n=0, 1..., for which offset=0. - Karol A. Penson (penson(AT)lptl.jussieu.fr), Oct 11 2001

Expansion of x^2*C^5, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers (A000108) - Herbert Kociemba (kociemba(AT)t-online.de), May 02 2004

CROSSREFS

T(n, n+5) for n=0, 1, 2, ..., array T as in A047072.

A diagonal of any of the essentially equivalent arrays A009766, A030237, A033184, A059365, A099039, A106566, A130020, A047072.

Cf. A000108 A000245 A002057 A000344 A003517 A000588 A003518 A003519 A001392.

Sequence in context: A094828 A030191 A093131 this_sequence A061278 A000758 A005283

Adjacent sequences: A000341 A000342 A000343 this_sequence A000345 A000346 A000347

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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