

A019609


Decimal expansion of Pi*e.


27



8, 5, 3, 9, 7, 3, 4, 2, 2, 2, 6, 7, 3, 5, 6, 7, 0, 6, 5, 4, 6, 3, 5, 5, 0, 8, 6, 9, 5, 4, 6, 5, 7, 4, 4, 9, 5, 0, 3, 4, 8, 8, 8, 5, 3, 5, 7, 6, 5, 1, 1, 4, 9, 6, 1, 8, 7, 9, 6, 0, 1, 1, 3, 0, 1, 7, 9, 2, 2, 8, 6, 1, 1, 1, 5, 7, 3, 3, 0, 8, 0, 7, 5, 7, 2, 5, 6, 3, 8, 6, 9, 7, 1, 0, 4, 7, 3, 9, 4
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OFFSET

1,1


COMMENTS

Pi*e ~= 316211059661164487904100 / 37028208538575230865001.  Alexander R. Povolotsky, Aug 06 2009
Pi*e ~= 2*( sum(1/product(2*k1, k=1...n), n=1...infinity ) + 725013737/1105744026 )^2.  Alexander R. Povolotsky, Aug 08 2009
Not known to be irrational (though of course conjectured transcendental), see e.g. Klee & Wagon.  Charles R Greathouse IV, Jul 23 2015


REFERENCES

Victor Klee and Stan Wagon, Old and New Unsolved Problems in Plane Geometry and Number Theory, Mathematical Association of America (1991). Problem 22, p. 243.


LINKS

Harry J. Smith, Table of n, a(n) for n = 1..20000


FORMULA

Lim_{k>inf} 4k/u(k)^2 where u(1)=0, u(2)=1, u(k+2) = u(k+1) + u(k)/(2k).  Benoit Cloitre, Aug 14 2003


EXAMPLE

8.53973422267356706546355086954657449503488853576511496187960113...


MATHEMATICA

RealDigits[N[Pi*E, 6! ]][[1]] (* Vladimir Joseph Stephan Orlovsky, Jun 18 2009 *)


PROG

(PARI) default(realprecision, 20080); x=Pi*exp(1); for (n=1, 20000, d=floor(x); x=(xd)*10; write("b019609.txt", n, " ", d)); \\ Harry J. Smith, Apr 27 2009


CROSSREFS

A159822 is the continued fraction for Pi*e.
Sequence in context: A011466 A154509 A081885 * A093341 A134973 A030437
Adjacent sequences: A019606 A019607 A019608 * A019610 A019611 A019612


KEYWORD

nonn,cons


AUTHOR

N. J. A. Sloane


EXTENSIONS

Checked by Neven Juric (neven.juric(AT)apisit.hr), Feb 04 2008


STATUS

approved



