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 A019609 Decimal expansion of Pi*e. 36
 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 (list; constant; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Pi*e ~= 316211059661164487904100 / 37028208538575230865001. - Alexander R. Povolotsky, Aug 06 2009 Pi*e ~= 2*( Sum_{k>=1} (1/Product_{k=1..n}(2*k-1) ) + 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=(x-d)*10; write("b019609.txt", n, " ", d)); \\ Harry J. Smith, Apr 27 2009 (MAGMA) SetDefaultRealField(RealField(100)); R:= RealField(); Pi(R)*Exp(1); // G. C. Greubel, Aug 24 2018 CROSSREFS A159822 is the continued fraction for Pi*e. Cf. A000796 (Pi), A001113 (e). Sequence in context: A011466 A154509 A081885 * A093341 A134973 A030437 Adjacent sequences:  A019606 A019607 A019608 * A019610 A019611 A019612 KEYWORD nonn,cons AUTHOR EXTENSIONS Checked by Neven Juric (neven.juric(AT)apis-it.hr), Feb 04 2008 STATUS approved

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Last modified December 18 08:16 EST 2018. Contains 318219 sequences. (Running on oeis4.)