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A105647 Increasing numbers whose digits satisfy the" Fractal Jump" rule: 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, whose digits are concatenated to form increasing numbers. 0

%I

%S 2,52,55,522,2252,5522,22522,222522,2222222,2225225,2522525,22252522,

%T 25525252

%N Increasing numbers whose digits satisfy the" Fractal Jump" rule: 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, whose digits are concatenated to form increasing numbers.

%e Take the first digit: 2. Jump over the next two digits (5 and 2) and take the next one: 5. Jump over the next five digits (5 5 2 2 2) and take the next one: 2 (the second 2 of number 2252). Jump over the next two digits (5 2) and take the next one: 5 (the first 5 of number 5522), etc. The digits taken: 2 5 2 5... constitute the sequence itself.

%Y Cf. A105395, A105396, A105397, A105398.

%K base,easy,nonn

%O 2,1

%A Eric Angelini & _Alexandre Wajnberg_, May 03 2005

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Last modified January 18 14:07 EST 2021. Contains 340254 sequences. (Running on oeis4.)