login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A281375 a(n) = floor(2^(n+1)/n). 1
4, 4, 5, 8, 12, 21, 36, 64, 113, 204, 372, 682, 1260, 2340, 4369, 8192, 15420, 29127, 55188, 104857, 199728, 381300, 729444, 1398101, 2684354, 5162220, 9942053, 19173961, 37025580, 71582788, 138547332, 268435456, 520602096, 1010580540, 1963413621, 3817748707, 7429132620, 14467258260, 28192605840, 54975581388 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
FORMULA
a(n) = A053639(n) if n is in A000079, otherwise A053639(n)-1.
a(2k-1) = A191636(k) for k > 1.
a(n) = (2^(n+1)-A112983(n))/n.
MAPLE
seq(floor(2^(n+1)/n), n=1..50); # Robert Israel, Jan 20 2017
PROG
(PARI) a(n) = 2^(n+1)\n \\ Felix Fröhlich, Jan 20 2017
CROSSREFS
Sequence in context: A198999 A095945 A072231 * A214070 A096641 A155693
KEYWORD
nonn,easy
AUTHOR
Robert Israel, Jan 20 2017
STATUS
approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 19 02:27 EDT 2024. Contains 374388 sequences. (Running on oeis4.)