

A277680


Inverse of the permutation A277679 of the natural numbers.


2



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, 24, 34, 33, 40, 28, 30, 22, 36, 35, 38, 41, 51, 31, 42, 43, 49, 39, 53, 50, 61, 62, 72, 29, 44, 45, 47, 37, 55, 48, 63, 64, 70, 46, 65, 52, 59, 60, 74, 73, 84, 54
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OFFSET

1,2


COMMENTS

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


LINKS

Clark Kimberling, Table of n, a(n) for n = 1..10000
Index entries for sequences that are permutations of the natural numbers


MATHEMATICA

x = Range[500];
NestWhile[# + 1 &, 1, (t = 1/2 # (1 + #);
x = Flatten[{Take[x, t],
Map[Reverse, Partition[Drop[x, t], # + 1]]}];
Length[x] > t) &]; x (* A277679 *)
Take[Ordering[#], Position[Differences[Sort[#]], Except[1]][[2]][[1]]]&[x] (* A277680 *) (* Peter J. C. Moses, Nov 13 2016 *)


CROSSREFS

Cf. A000027, A277679, A007062, A057030.
Sequence in context: A083236 A302717 A277820 * A303764 A079973 A267150
Adjacent sequences: A277677 A277678 A277679 * A277681 A277682 A277683


KEYWORD

nonn,look,easy


AUTHOR

Clark Kimberling, Nov 14 2016


STATUS

approved



