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A053316 a(n) contains n digits (either '2' or '3') and is divisible by 2^n. 2
2, 32, 232, 3232, 23232, 223232, 2223232, 32223232, 232223232, 3232223232, 23232223232, 323232223232, 3323232223232, 23323232223232, 323323232223232, 3323323232223232, 33323323232223232, 333323323232223232 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..999

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 a(n-1) is divisible by 2^n then a(n) begins with a 2, if not then a(n) begins with a 3.

MAPLE

A[1]:= 2:

for n from 2 to 100 do

   if A[n-1] mod 2^n = 0 then A[n]:= A[n-1]+2*10^(n-1)

   else A[n]:= A[n-1]+3*10^(n-1)

     fi

od:

seq(A[i], i=1..100); # Robert Israel, Oct 27 2019

CROSSREFS

Cf. A023397, A050621, A050622, A035014.

Sequence in context: A169833 A228582 A128789 * A053053 A053054 A224903

Adjacent sequences:  A053313 A053314 A053315 * A053317 A053318 A053319

KEYWORD

base,nonn

AUTHOR

Henry Bottomley, Mar 06 2000

EXTENSIONS

Formula corrected by Robert Israel, Oct 27 2019

STATUS

approved

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Last modified August 8 06:27 EDT 2020. Contains 336290 sequences. (Running on oeis4.)