A139334 Starts with 2; has two properties: concatenation of its digits is same string as concatenation of digits of its first differences and sequence and first differences have no term in common. When there is a choice in choosing the next term in the first differences, choose the smallest number not yet present in either the sequence or its first differences.

2, 24, 28, 311, 312, 325, 337, 340, 365, 398, 405, 3808, 3814, 3819, 3858, 3866, 3906, 3959, 4039, 4122, 4203, 4246, 5065, 5103, 5161, 5547, 5610, 5700, 6339, 6398, 6801, 6810, 6851, 7075, 7095, 7129, 7375, 7425, 7490, 8000, 8035, 8051, 8066, 8120, 8195, 8805

Offset

1,1

References

E. Angelini, "Jeux de suites", in Dossier Pour La Science, pp. 32-35, Volume 59 (Jeux math'), April/June 2008, Paris.

Links

Lars Blomberg, Table of n, a(n) for n = 1..10000

Example

The first differences are 22, 4, 283, 1, 13, 12, 3, 25, 33, 7, 3403, ...

Crossrefs

Sequence in context: A064818 A349724 A022374 * A212759 A112660 A330526

Adjacent sequences: A139331 A139332 A139333 * A139335 A139336 A139337

Keyword

nonn,base

Author

N. J. A. Sloane (based on Angelini's article), Jun 08 2008

Extensions

Extended through a(12) by Eric Angelini, Jul 18 2008

Status

approved