A066646 Arrange the permutations of {1..m} in lexicographic order. Sequence gives indices of permutations of orders 1 or 2.

1, 2, 3, 6, 7, 8, 15, 17, 22, 24, 25, 26, 27, 30, 55, 56, 61, 68, 81, 83, 87, 95, 106, 108, 112, 120, 121, 122, 123, 126, 127, 128, 135, 137, 142, 144, 265, 266, 267, 270, 289, 290, 315, 317, 340, 342, 391, 392, 397, 404, 415, 416, 445, 451, 470, 476, 513, 515

Offset

1,2

Comments

Independent of choice of m as long as m! exceeds index.

Links

Table of n, a(n) for n=1..58.

Example

Take m=4, say. The first few permutations are 1234, 1243, 1324, 1342, 1423, 1432, 2134, 2143, 2314, ... and numbers 1,2,3,6,7,8,... have orders 1 or 2. This gives the first 6 terms.

Crossrefs

Sequence in context: A344342 A035346 A030164 * A215488 A110920 A296414

Adjacent sequences: A066643 A066644 A066645 * A066647 A066648 A066649

Keyword

easy,nice,nonn

Author

Ian Mooney, Jan 09 2002

Status

approved