A284515 - OEIS

%I #11 Dec 11 2020 17:45:31

%S 100,1000,1002,1100,1102,10000,10002,10020,10022,10100,10102,10120,

%T 10122,11000,11002,11020,11022,11100,11102,11120,11122,30000,30002,

%U 30020,30022,30100,30102,30120,30122,31000,31002,31020,31022,31100,31102,31120,31122,100000,100002,100004,100020,100022,100024,100100,100102,100104,100120

%N "Inside numbers". Pick a term "t" and one of its digits "d". Now jump to the right over d digits if "d" is odd, and to the left over d digits if "d" is even. Whatever the "d" you choose, you will stay on "t".

%C The sequence is started with a(1) = 100 and always extended with the smallest integer not yet present and not leading to a contradiction.

%H Jean-Marc Falcoz, <a href="/A284515/b284515.txt">Table of n, a(n) for n = 1..2441</a>

%e Pick the digit "1" of the first term, 100. This "1" says that you should jump over 1 digit to the right (as "1" is odd). You'll land on the second "0" of 100.

%e Pick the leftmost digit "0" of the same term, 100. This "0" says that you should jump over 0 digit to the left (as "0" is even). You slide (land) on the "1" of 100.

%e Pick the rightmost digit "0" of 100. This "0" says that you should jump over 0 digit to the left (as "0" is even). You slide (land) on the first "0" of 100.

%e We see that any of those possible three movements leaves you "inside" the chosen term "t".

%Y Cf. A284591 (full inside numbers).

%K nonn,base

%O 1,1

%A _Eric Angelini_ and _Jean-Marc Falcoz_, Mar 28 2017