A080719 Replace decimal digits with their binary values and convert back to decimal representation.

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

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