A175057 - OEIS

%I #10 Sep 03 2017 22:16:40

%S 1,3,2,7,4,5,6,15,8,9,11,12,13,14,31,16,17,19,10,23,24,25,27,28,29,30,

%T 63,32,33,35,18,39,20,21,22,47,48,49,51,26,55,56,57,59,60,61,62,127,

%U 64,65,67,34,71,36,37,38,79,40,41,43,44,45,46,95,96,97,99,50,103,52,53,54

%N a(n) = decimal equivalent of {A175054(n) written in binary, and each run of 0's reduced in length by one digit}.

%C This is a permutation of the positive integers. Sequence A175058 is its inverse permutation.

%H Michael De Vlieger, <a href="/A175057/b175057.txt">Table of n, a(n) for n = 1..10000</a>

%t Map[FromDigits[#, 2] &@ Flatten@ # &, Select[Array[Split@ IntegerDigits[#, 2] &, 216], FreeQ[#, {0}] &] /. w_List /; First@ w == 0 :> Most@ w] (* _Michael De Vlieger_, Sep 03 2017 *)

%Y Cf. A175054, A175058, A175055, A175056, A175059, A175060

%K base,nonn

%O 1,2

%A _Leroy Quet_, Dec 08 2009

%E Extended by _Ray Chandler_, Dec 18 2009