A338380 Replace every term a(n) by the pair [a(n), a(n)] to form a new sequence S: S is the succession of the absolute differences of the starting sequence.

1, 2, 3, 5, 7, 10, 13, 18, 23, 16, 9, 19, 29, 42, 55, 73, 91, 68, 45, 61, 77, 86, 95, 114, 133, 104, 75, 117, 159, 214, 269, 342, 415, 324, 233, 165, 97, 142, 187, 248, 309, 232, 155, 241, 327, 422, 517, 631, 745, 612, 479, 375, 271, 196, 121, 238, 355, 514, 673, 887, 1101, 832, 563, 905, 1247, 1662, 2077

Offset

1,2

Comments

This is the lexicographically earliest sequence of distinct positive terms with this property.

Links

Carole Dubois, Table of n, a(n) for n = 1..5001

Example

The successive absolute differences between two successive terms are 1, 1, 2, 2, 3, 3, 5, 5, 7, 7, 10, 10, 13, 13, 18, 18, 23, 23, 16, 16, 9, 9,... which is the sequence itself with every term duplicated.

Crossrefs

Cf. A033485 (same sequence, but strictly monotonically increasing).

Sequence in context: A319470 A115001 A349060 * A309408 A347647 A008766

Adjacent sequences: A338377 A338378 A338379 * A338381 A338382 A338383

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, Nov 05 2020

Status

approved