A105647 Lexicographically earliest sequence of increasing numbers whose digits satisfy the "Fractal Jump" rule using only the digits 2 and 5: keep the first digit "d" of the sequence, then jump over the next "d" digits and keep the digit "e" on which you have landed. Jump now over the next "e" digits and keep the digit "f" on which you have landed, etc. The succession "def..." of kept digits is the sequence itself.

2, 5, 25, 52, 55, 222, 252, 255, 552, 555, 2222, 5222, 5252, 5255, 22222, 22252, 22522, 22525, 22555, 25222, 52222, 55222, 55522, 55525, 55552, 55555, 222522, 225222, 225225, 225522, 252222, 252225, 522222, 2225222, 2225252, 2225255, 5222225, 5222522, 5225222

Offset: 1

Author

Eric Angelini and Alexandre Wajnberg, May 03 2005

Keywords

• base
• easy
• nonn

Examples

			The sequence and the "kept" digits begin
  2, 5, 25, 52, 55, 222, 252, 255, 552, ...
  ^      ^           ^    ^         ^
  2      5           2    5         5
		

Links

• Tyler Busby, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A105395, A105396, A105397, A105398.

Extensions

Corrected and extended by Tyler Busby, Jan 08 2023