A277427 Prime permutations, ordered lexicographically.

1, 2, 1, 3, 1, 2, 3, 2, 1, 4, 1, 2, 3, 4, 1, 3, 2, 4, 2, 1, 3, 4, 2, 3, 1, 4, 3, 1, 2, 4, 3, 2, 1, 5, 1, 2, 3, 4, 5, 1, 2, 4, 3, 5, 1, 3, 2, 4, 5, 1, 3, 4, 2, 5, 1, 4, 2, 3, 5, 1, 4, 3, 2, 5, 2, 1, 3, 4, 5, 2, 1, 4, 3, 5, 2, 3, 1, 4, 5, 2, 3, 4, 1, 5, 2, 4, 1, 3, 5, 2, 4, 3, 1, 5, 3, 1, 2, 4, 5, 3, 1, 4, 2, 5, 3, 2, 1

Offset

1,2

Comments

A permutation of {1..n} is prime (in the sense of A215474) iff it is of the form (n, q_1, q_2, ..., q_{n-1}).

Row n in the triangle consists of all permutations consisting of n followed by a permutation of 1..n-1, in lexicographic order.

Links

Gus Wiseman, Table of n, a(n) for n = 1..5912

Example

The sequence of prime permutations begins:
1,
21,
312, 321,
4123, 4132, 4213, 4231, 4312, 4321,
...

Maple

seq(op(map(t -> (n, op(t)), combinat:-permute(n-1))), n=1..6); # Robert Israel, Nov 07 2016

Mathematica

row[n_] := Join[{n}, #]& /@ Permutations[Range[n-1]];
Array[row, 5] // Flatten (* Jean-François Alcover, Apr 10 2019 *)

Crossrefs

Cf. A215474, A254040, A060223, A005117.

Sequence in context: A358921 A132589 A054843 * A231631 A280700 A356149

Adjacent sequences: A277424 A277425 A277426 * A277428 A277429 A277430

Keyword

nonn,tabf

Author

Gus Wiseman, Oct 14 2016

Status

approved