A006524 Egyptian fraction for 1/ Pi. (Formerly M3509)

4, 15, 609, 845029, 1010073215739, 1300459886313272270974271, 1939680952094609786557359582286462958434022504402

Offset

1,1

References

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

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..11 [a(11) corrected by Georg Fischer, Jun 04 2019]

H. P. Robinson, Letter to N. J. A. Sloane, Sep 1975

Eric Weisstein's World of Mathematics, Egyptian Fraction

Index entries for sequences related to the number Pi

Index entries for sequences related to Egyptian fractions

Mathematica

a = {}; k = N[1/Pi, 1000]; Do[s = Ceiling[1/k]; AppendTo[a, s]; k = k - 1/s, {n, 1, 10}]; a (* Artur Jasinski, Sep 22 2008 *)

Prog

(PARI) x = 1/Pi;
f(x, k) = if(k<1, x, f(x, k - 1) - 1/n(x, k));
n(x, k) = ceil(1/f(x, k - 1));
for(k = 1, 7, print1(n(x, k), ", ") \\ Indranil Ghosh, Mar 27 2017

Crossrefs

Sequence in context: A000881 A354462 A109923 * A299683 A341598 A295231

Adjacent sequences: A006521 A006522 A006523 * A006525 A006526 A006527

Keyword

nonn,frac

Author

N. J. A. Sloane, Robert G. Wilson v

Extensions

More terms from Herman P. Robinson

Offset changed to 1 by Indranil Ghosh, Mar 27 2017

Status

approved