login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A100340 Numerators of the convergents in the continued fraction expansion for the constant given by A100338, where the partial quotients equal A006519 (greatest power of 2 dividing n). 4
1, 3, 4, 19, 23, 65, 88, 769, 857, 2483, 3340, 15843, 19183, 54209, 73392, 1228481, 1301873, 3832227, 5134100, 24368627, 29502727, 83374081, 112876808, 986388545, 1099265353, 3184919251, 4284184604, 20321657667, 24605842271, 69533342209 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The convergents for the continued fraction of x are given by A100340(n)/A100341(n) and the convergents for the continued fraction of 2*x are given by A100342(n)/A100343(n), where A100342(n)/A100343(n) = 2*A100340(n)/A100341(n) for all n.

FORMULA

a(1) = 1, a(2) = 3, a(n) = a(n-1)*A006519(n) + a(n-2).

EXAMPLE

The constant is x=1.353871128429882374388894084016608124227333416812...

contfrac(x) = [1;2,1,4,1,2,1,8,1,2,1,4,1,2,1,16,...A006519(n),... ].

PROG

(PARI) a(n)=if(n==1, 1, if(n==2, 3, a(n-1)*2^valuation(n, 2)+a(n-2)))

CROSSREFS

Cf. A100338, A006519, A100341, A100342, A100343.

Sequence in context: A197564 A020344 A143150 * A042175 A041703 A036253

Adjacent sequences:  A100337 A100338 A100339 * A100341 A100342 A100343

KEYWORD

cofr,nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Nov 18 2004

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 08:39 EST 2012. Contains 205998 sequences.