login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A131549 Least power of 3 having exactly n consecutive 4's in its decimal representation. 1

%I

%S 5,12,55,308,510,2340,7286,9670,125406,222961,847169,639226,6250771,

%T 14929721

%N Least power of 3 having exactly n consecutive 4's in its decimal representation.

%C No more terms < 2*10^7.

%e a(3)=55 because 3^55(i.e. 174449211009120179071170507) is the smallest power of 3 to contain a run of 3 consecutive fours in its decimal form.

%t a = ""; Do[ a = StringJoin[a, "4"]; b = StringJoin[a, "4"]; k = 1; While[ StringPosition[ ToString[3^k], a] == {} || StringPosition[ ToString[3^k], b] != {}, k++ ]; Print[k], {n, 1, 10} ]

%K more,nonn,base

%O 1,1

%A _Shyam Sunder Gupta_, Aug 26 2007

%E a(11)-a(14) from _Lars Blomberg_, Feb 02 2013

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

License Agreements, Terms of Use, Privacy Policy .

Last modified December 4 15:24 EST 2016. Contains 278750 sequences.