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A224896 First occurrence of n consecutive n's in the decimal expansion of the Champernowne constant. 0
1, 34, 56, 1222, 1555, 25554, 29998, 433330, 7988888882, 1101010101010, 1222222222222, 158585858585858, 172727272727272, 21515151515151514, 23131313131313130, 2797979797979797978, 2979797979797979796, 352525252525252525250, 372727272727272727270 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Earls sequence for the Champernowne constant.
LINKS
Eric Weisstein's World of Mathematics, Champernowne Constant Digits
Eric Weisstein's World of Mathematics, Earls Sequence
EXAMPLE
C = 0.12345678910111213141516171819202122232425262728293031323334..., so
a(1) = 1 (one 1 first appears at digit 1 after the decimal point),
a(2) = 34 (two 2s first occur starting at digit 34),
a(3) = 56 (three 3s first occur starting at digit 56).
MATHEMATICA
r[d_, n_] := FromDigits@Flatten[IntegerDigits /@ Table[d, {n}]]; up[n_] := Block[{z = IntegerLength@n}, n*z + (10 - 10^z)/9]; Table[ If[n == 9, up[899999999] + 1, up[r[n, Floor[n/2] + 1]]], {n, 19}] (* Giovanni Resta, Jul 29 2013 *)
CROSSREFS
Sequence in context: A055574 A294173 A176687 * A103558 A103686 A211715
KEYWORD
nonn,base
AUTHOR
Eric W. Weisstein, Jul 24 2013
EXTENSIONS
a(9) from Eric W. Weisstein, Jul 28 2013
a(10)-a(19) from Giovanni Resta, Jul 29 2013
STATUS
approved

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Last modified February 29 13:45 EST 2024. Contains 370425 sequences. (Running on oeis4.)