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

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A080719 Replace decimal digits by their binary values and convert back to decimal representation. 3
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 2, 3, 6, 7, 12, 13, 14, 15, 24, 25, 4, 5, 10, 11, 20, 21, 22, 23, 40, 41, 6, 7, 14, 15, 28, 29, 30, 31, 56, 57, 8, 9, 18, 19, 36, 37, 38, 39, 72, 73, 10, 11, 22, 23, 44, 45, 46, 47, 88, 89, 12, 13, 26, 27, 52, 53, 54, 55, 104, 105, 14, 15, 30, 31, 60, 61, 62 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

m is a local maximum iff m == 9 modulo 10 (see A017377).

A257831 seen as binary numbers: A007088(a(n)) = A257831(n). - Reinhard Zumkeller, May 10 2015

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

EXAMPLE

n=27 -> '2''7' -> '10''111' -> '10111' -> 23: a(27)=23.

See also A257831.

MATHEMATICA

Table[FromDigits[Flatten[IntegerDigits[#, 2]&/@IntegerDigits[n]], 2], {n, 80}] (* Harvey P. Dale, Aug 30 2014 *)

PROG

(Haskell)

import Data.Maybe (mapMaybe)

a080719 = foldr (\b v -> 2 * v + b) 0 .

           concat . mapMaybe (flip lookup bin) . a031298_row

            where bin = zip [0..9] a030308_tabf

-- Reinhard Zumkeller, May 10 2015

(Python)

def A080719(n):

....return int(''.join((format(int(d), 'b') for d in str(n))), 2)

# Chai Wah Wu, May 10 2015

CROSSREFS

Cf. A007088.

Cf. A257831, A030308, A031298.

Sequence in context: A038506 A091047 A068505 * A049105 A125959 A043269

Adjacent sequences:  A080716 A080717 A080718 * A080720 A080721 A080722

KEYWORD

nonn,base

AUTHOR

Reinhard Zumkeller, Mar 06 2003

EXTENSIONS

a(0)=0 prepended and offset changed by Reinhard Zumkeller, May 10 2015

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy .

Last modified December 8 02:07 EST 2016. Contains 278902 sequences.