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%I #19 Mar 31 2017 21:43:37
%S 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,
%T 40,41,6,7,14,15,28,29,30,31,56,57,8,9,18,19,36,37,38,39,72,73,10,11,
%U 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
%N Replace decimal digits with their binary values and convert back to decimal representation.
%C m is a local maximum iff m == 9 modulo 10 (see A017377).
%C A257831 seen as binary numbers: A007088(a(n)) = A257831(n). - _Reinhard Zumkeller_, May 10 2015
%H Reinhard Zumkeller, <a href="/A080719/b080719.txt">Table of n, a(n) for n = 0..10000</a>
%e n=27 -> '2''7' -> '10''111' -> '10111' -> 23: a(27)=23.
%e See also A257831.
%t Table[FromDigits[Flatten[IntegerDigits[#,2]&/@IntegerDigits[n]],2],{n,80}] (* _Harvey P. Dale_, Aug 30 2014 *)
%o (Haskell)
%o import Data.Maybe (mapMaybe)
%o a080719 = foldr (\b v -> 2 * v + b) 0 .
%o concat . mapMaybe (flip lookup bin) . a031298_row
%o where bin = zip [0..9] a030308_tabf
%o -- _Reinhard Zumkeller_, May 10 2015
%o (Python)
%o def A080719(n):
%o ....return int(''.join((format(int(d),'b') for d in str(n))),2)
%o # _Chai Wah Wu_, May 10 2015
%Y Cf. A007088.
%Y Cf. A257831, A030308, A031298.
%K nonn,base
%O 0,3
%A _Reinhard Zumkeller_, Mar 06 2003
%E a(0)=0 prepended and offset changed by _Reinhard Zumkeller_, May 10 2015
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