A102254 Begin with 3, multiply each digit by 2, keeping the memory of the groupings of the preceding digits.

3, 6, 12, 24, 48, 816, 16212, 212424, 424848, 84816816, 1681621216212, 21216212424212424, 424212424848424848, 8484248481681684816816, 1681684816816212162121681621216212, 21216212168162121621242421242421216212424212424

Offset

1,1

Links

Table of n, a(n) for n=1..16.

Formula

d*2, beginning with 3.

Example

Read a(3)=12 which produces a(4)=24 because 1*2=2 and 2*2=4.

Mathematica

Flatten[ NestList[ Function[x, FromDigits[ Flatten[ IntegerDigits[2IntegerDigits[ x]]] ]], 3, 15]] (* Robert G. Wilson v, Feb 21 2005 *)

Crossrefs

Sequence in context: A099844 A165929 A084717 * A278666 A007239 A088970

Adjacent sequences: A102251 A102252 A102253 * A102255 A102256 A102257

Keyword

base,easy,nonn

Author

Alexandre Wajnberg and Eric Angelini, Feb 18 2005

Extensions

More terms from Robert G. Wilson v, Feb 21 2005

Status

approved