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A094008 Primes which are the denominators of convergents of the continued fraction expansion of e. 4
3, 7, 71, 18089, 10391023, 781379079653017, 2111421691000680031, 1430286763442005122380663256416207 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

The position of a(n) in A000040 (the prime numbers) is A102049(n) = A000720(a(n)). - Jonathan Sondow (jsondow(AT)alumni.princeton.edu), Dec 27 2004

The next term has 166 digits. [From Harvey P. Dale, Aug 23 2011]

REFERENCES

E. B. Burger, Diophantine Olympics ..., Amer. Math. Monthly, 107 (Nov. 2000), 822-829.

J. Sondow, A geometric proof that e is irrational and a new measure of its irrationality, Amer. Math. Monthly, 113 (2006) 637-641 (article), 114 (2007) 659 (addendum).

LINKS

J. Sondow, A geometric proof that e is irrational and a new measure of its irrationality

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics\.

FORMULA

a(n) = A007677(A094007(n)) = A000040(A102049(n)).

EXAMPLE

a(1) = 3 because 3 is the first prime denominator of a convergent, 8/3, of the simple continued fraction for e

MATHEMATICA

Block[{$MaxExtraPrecision=1000}, Select[Denominator[Convergents[E, 500]], PrimeQ]] (* From Harvey P. Dale, Aug 23 2011 *)

CROSSREFS

Cf. A094007. See also A000040, A000720, A007677, A102049.

Sequence in context: A127179 A113841 A128072 * A078552 A091259 A088647

Adjacent sequences:  A094005 A094006 A094007 * A094009 A094010 A094011

KEYWORD

nonn

AUTHOR

Jonathan Sondow (jsondow(AT)alumni.princeton.edu), Apr 20 2004

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Last modified February 14 18:05 EST 2012. Contains 205664 sequences.