A102255 Slowest increasing sequence beginning with 3 whose digits satisfy the rule d*2.

3, 6, 12, 24, 48, 81, 616, 2122, 12424, 42484, 88481, 681616, 816212, 1621221, 2162124, 2421242, 4424212, 42484842, 48488484, 248481681, 684816816, 1681684816, 8162121621, 21681621216, 212212162121, 681621216212

Offset

1,1

Comments

Same digits as A102254.

Links

Table of n, a(n) for n=1..26.

Formula

d*2, beginning with 3.

Example

Read a(6)=81, which produces a(7)=162 because 8*2=16 and 1*2=2.

Mathematica

t = Flatten[ NestList[ Function[x, Flatten[ IntegerDigits[2IntegerDigits[x]]]], 3, 15]]; a = 0; l = {}; Do[k = 1; While[fd = FromDigits[ Take[t, k]]; a > fd, k++ ]; t = Drop[t, k]; AppendTo[l, fd]; a = fd, {n, 27}]; l (* Robert G. Wilson v, Feb 21 2005 *)

Crossrefs

Sequence in context: A115807 A366277 A322676 * A192871 A002910 A001668

Adjacent sequences: A102252 A102253 A102254 * A102256 A102257 A102258

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