A266926 a(0)=0, a(1)=1, a(2)=10; for n>2, a(n) = concat(a(1), ..., a(n-1)).

0, 1, 10, 110, 110110, 110110110110, 110110110110110110110110, 110110110110110110110110110110110110110110110110, 110110110110110110110110110110110110110110110110110110110110110110110110110110110110110110110110

Offset

0,3

Comments

Decimal conversions: 0, 1, 2, 6, 54, 3510, 14380470, 241264265751990, 67909853583655146508751957430, ... . (See A267348.) - Michael De Vlieger, Jan 06 2016

After 10, a(n) is '110' repeated 2^(n-3) times. Therefore, for n>3, a(n) is the concatenation of a(n-1) with itself.

After 1, each term with the 0's omitted is a member of A136308.

The number of digits in a(n) is A098011(n+1).

The number of digits in a(n+2)/a(n+1) gives A103204 with 2 repeated.

Links

Table of n, a(n) for n=0..8.

Formula

a(n) = 110*(10^(3*2^(n-3))-1)/999 for n>2. - Bruno Berselli, Jan 29 2016

Example

a(3) = concat(1, 10, 110) = 110110.
a(4) = concat(1, 10, 110, 110110) = 110110110110.

Mathematica

a = {0, 1}; Do[AppendTo[a, FromDigits@ Flatten@ Map[IntegerDigits@ # &, If[n < 2, Reverse@ a, a]]], {n, 8}]; a (* Michael De Vlieger, Jan 06 2016 *)

Prog

(Magma) [n le 2 select n*5^(n-1) else 110*(10^(3*2^(n-3))-1)/999: n in [0..8]]; // Bruno Berselli, Jan 29 2016

Crossrefs

Cf. A000079, A098011, A103204, A136308, A267348.

Sequence in context: A036603 A092500 A092501 * A209234 A282070 A282491

Adjacent sequences: A266923 A266924 A266925 * A266927 A266928 A266929

Keyword

nonn,base,easy

Author

Giovanni Teofilatto, Jan 06 2016

Extensions

Definition by Michael De Vlieger, Jan 06 2016

Edited by Editors of the OEIS, Jan 29 2016

Status

approved