login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A217190 a(n) is the number of digits in the decimal representation of the smallest power of 11 that contains n consecutive identical digits. 0

%I #10 Apr 30 2013 20:16:18

%S 1,2,9,41,163,502,1378,3107,9834,41530,223636,308352,308352

%N a(n) is the number of digits in the decimal representation of the smallest power of 11 that contains n consecutive identical digits.

%C Number of digits in 11^k is equal to floor(1 + k*log_10(11)).

%t k = 0; Join[{1}, Table[While[d = IntegerDigits[11^k]; prt = Partition[Differences[d], n - 1, 1]; ! MemberQ[prt, Table[0, {n - 1}]], k++]; Length[d], {n, 2, 8}]] (* _T. D. Noe_, Oct 03 2012 *)

%Y Cf. A215731, A215737.

%K nonn,base

%O 1,2

%A _V. Raman_, Sep 27 2012

%E a(10)-a(13) added by _V. Raman_, Apr 30 2012, in correspondence with A215731.

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 11:27 EDT 2024. Contains 371838 sequences. (Running on oeis4.)