A110398 a(1) = 11. a(n) is obtained by filling the space between neighboring digits in a(n-1) with their sum.

11, 121, 13231, 143525341, 15473857275837451, 1659411710311813512792971251381131071149561, 176115149134512187811033412198914385613297169112119167813275614311891214341107781215413914511671

Offset

1,1

Comments

If we consider a(1) = 11 to be a binary number and recursively construct a(n) by filling the space between neighboring bits in a(n-1) with their binary sum we obtain the binary sequence 11, 1101, 11011011, 110110111011011011101, .... This sequence converges to the Sturmian word A080764. - Peter Bala, Jan 30 2015

Links

Table of n, a(n) for n=1..7.

Example

a(2) = 121; for a(3), in 1-2-1 the two (-) are replaced by 1+2 = 3 hence a(3)=13231.

Crossrefs

Cf. A080764, A216208.

Sequence in context: A342233 A082776 A216208 * A176595 A067218 A368114

Adjacent sequences: A110395 A110396 A110397 * A110399 A110400 A110401

Keyword

base,easy,nonn

Author

Amarnath Murthy, Jul 29 2005

Extensions

More terms from Maire O'Neill (mbo5001(AT)psu.edu), Oct 04 2005

Status

approved