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A053312 a(n) contains n digits (either '1' or '2') and is divisible by 2^n. 3
2, 12, 112, 2112, 22112, 122112, 2122112, 12122112, 212122112, 1212122112, 11212122112, 111212122112, 1111212122112, 11111212122112, 211111212122112, 1211111212122112, 11211111212122112, 111211111212122112 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..18.

FORMULA

a(n)=a(n-1)+10^(n-1)*(2-[a(n-1)/2^(n-1) mod 2]) i.e. a(n) ends with a(n-1); if (n-1)-th term is divisible by 2^n then n-th term begins with a 2, if not then n-th term begins with a 1.

CROSSREFS

Cf. A023396, A050621, A050622, A035014.

Sequence in context: A185190 A227460 A091481 * A091854 A141141 A128571

Adjacent sequences:  A053309 A053310 A053311 * A053313 A053314 A053315

KEYWORD

base,nonn

AUTHOR

Henry Bottomley, Mar 06 2000

STATUS

approved

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Last modified September 2 17:19 EDT 2014. Contains 246362 sequences.