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 A277680 Inverse of the permutation A277679 of the natural numbers. 2

%I

%S 1,3,2,5,6,8,4,10,9,12,13,19,7,14,15,17,11,21,18,25,26,32,16,27,20,23,

%T 24,34,33,40,28,30,22,36,35,38,41,51,31,42,43,49,39,53,50,61,62,72,29,

%U 44,45,47,37,55,48,63,64,70,46,65,52,59,60,74,73,84,54

%N Inverse of the permutation A277679 of the natural numbers.

%C This is a permutation of the natural numbers, with inverse permutation A277679.

%H Clark Kimberling, <a href="/A277680/b277680.txt">Table of n, a(n) for n = 1..10000</a>

%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>

%t x = Range[500];

%t NestWhile[# + 1 &, 1, (t = 1/2 # (1 + #);

%t x = Flatten[{Take[x, t],

%t Map[Reverse, Partition[Drop[x, t], # + 1]]}];

%t Length[x] > t) &]; x (* A277679 *)

%t Take[Ordering[#],Position[Differences[Sort[#]],Except[1]][[2]][[1]]]&[x] (* A277680 *) (* _Peter J. C. Moses_, Nov 13 2016 *)

%Y Cf. A000027, A277679, A007062, A057030.

%K nonn,look,easy

%O 1,2

%A _Clark Kimberling_, Nov 14 2016

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Last modified May 31 07:30 EDT 2020. Contains 334747 sequences. (Running on oeis4.)