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A002665 Continued fraction expansion of Lehmer's constant.
(Formerly M1549 N0605)
+0
6
0, 1, 1, 2, 5, 34, 985, 1151138, 1116929202845, 1480063770341062927127746, 1846425204836010506550936273411258268076151412465 (list; graph; listen)
OFFSET

0,4

REFERENCES

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

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340.

LINKS

Harry J. Smith, Table of n, a(n) for n=0,...,12

G. Xiao, Contfrac

Index entries for continued fractions for constants

FORMULA

With a different offset: a(0)=1, a(1)=1, a(n+1)=(b(n)+b(n-1)+1)*a(n-1), n >= 1, b()=A002065, with b(0)=0, b(1)=1, b(2)=3, ...

EXAMPLE

0.592632718201636... = 0 + 1/(1 + 1/(1 + 1/(2 + 1/(5 + ...)))) [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 14 2009]

PROGRAM

(PARI) { default(realprecision, 2000); Lehmers=0\

.592632718201636197104078604995701469084275407197161071099562608158\

2473523641600085106647842971012570511871834654238696349260297206760\

6827856079871979437487251403403000583692486915538640614660348566823\

4121548456364466428309378049800689911831849656961720121137594706234\

3698651457715202867734217229580516823444477688944508054163206155851\

2323623064379170223520781603669639276342712524885456742628397234194\

8611415554411186566073479238779804346634255316927539229973648634858\

7121833376712533276555297652866612606618578871362294940308903198431\

3907958405478989509947007489250053656329690017664408563598385209478\

3018218689521378489849677057873565373854975935206722986039362075285\

7617751097879568662935191278445393356845487461466799368867183574393\

7379165908437616570415794750776200309560115740427603024939939214964\

1936741717206542969539031755269515358434395672719151901688809817175\

9724906758187355999053854269057589569016230717484797270186090849699\

968957675960828498381969270404195036511309800972643309599823665; x=contfrac(Lehmers); for (n=1, 13, write("b002665.txt", n-1, " ", x[n])); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 14 2009]

CROSSREFS

Cf. A002794, A002795, A002665, A030125, A002065.

Starting with n=2, a(n)/a(n-2) are in A096407.

Cf. A030125 Decimal expansion. [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 14 2009]

Adjacent sequences: A002662 A002663 A002664 this_sequence A002666 A002667 A002668

Sequence in context: A114793 A027303 A052695 this_sequence A000665 A058882 A000659

KEYWORD

nonn,cofr,nice,easy

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from J. O. Shallit.

The first two terms were missing. Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 14 2009

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Last modified November 3 12:59 EST 2009. Contains 165766 sequences.


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