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A143233 Decimal expansion of the dimer constant. 2
2, 9, 1, 5, 6, 0, 9, 0, 4, 0, 3, 0, 8, 1, 8, 7, 8, 0, 1, 3, 8, 3, 8, 4, 4, 5, 6, 4, 6, 8, 3, 9, 4, 9, 1, 8, 8, 6, 4, 0, 6, 6, 1, 5, 3, 9, 8, 5, 8, 3, 7, 2, 7, 0, 2, 6, 1, 0, 0, 1, 5, 6, 9, 1, 1, 1, 7, 4, 7, 6, 3, 6, 8, 8, 0, 4, 3, 8, 8, 6, 1, 7, 2, 6, 6, 2, 6, 8, 2, 4, 3, 0, 3, 1, 3, 4, 0, 5, 8, 9, 0, 8, 9, 7, 2 (list; constant; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

G. C. Greubel, Table of n, a(n) for n = 0..10000

Yong Kong, Monomer-dimer model in two-dimensional rectangular lattices with fixed dimer density, arXiv:cond-mat/0610690

Eric Weisstein's World of Mathematics, Domino Tiling

FORMULA

Equals Catalan/Pi.

Also equals integral_{t=-Pi..Pi} arccosh(sqrt(cos(t)+3)/sqrt(2))/(4*Pi) dt. - Jean-François Alcover, May 14 2014

EXAMPLE

0.29156090403081878013...

MATHEMATICA

RealDigits[Catalan/Pi, 10, 100][[1]] (* G. C. Greubel, Aug 24 2018 *)

PROG

(PARI) default(realprecision, 100); Catalan/Pi \\ G. C. Greubel, Aug 24 2018

(MAGMA) SetDefaultRealField(RealField(100)); R:=RealField(); Catalan(R)/Pi(R); // G. C. Greubel, Aug 24 2018

CROSSREFS

Cf. A000796, A006752.

Sequence in context: A244807 A021347 A011278 * A266264 A011216 A096250

Adjacent sequences:  A143230 A143231 A143232 * A143234 A143235 A143236

KEYWORD

nonn,cons

AUTHOR

Eric W. Weisstein, Jul 31 2008

STATUS

approved

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Last modified October 19 04:40 EDT 2019. Contains 328211 sequences. (Running on oeis4.)