A277680 Inverse of the permutation A277679 of the natural numbers.

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

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: A257793 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