This site is supported by donations to The OEIS Foundation.

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A131544 Least power of 3 having exactly n consecutive 9's in its decimal representation. 2
 2, 34, 35, 276, 1520, 2342, 8882, 32313, 164065, 265693, 1123487, 2421341, 6250773, 9995032 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS No more terms < 2*10^7. LINKS EXAMPLE a(3)=35 because 3^35 (i.e., 50031545098999707) is the smallest power of 3 to contain a run of 3 consecutive nines in its decimal form. MATHEMATICA a = ""; Do[ a = StringJoin[a, "9"]; b = StringJoin[a, "9"]; k = 1; While[ StringPosition[ ToString[3^k], a] == {} || StringPosition[ ToString[3^k], b] != {}, k++ ]; Print[k], {n, 1, 10} ] PROG (Python) def A131544(n): ....m, s = 1, '9'*n ....for i in range(1, 10**9): ........m *= 3 ........if s in str(m): ............return i ....return "search limit reached." # Chai Wah Wu, Dec 11 2014 CROSSREFS Sequence in context: A180342 A232591 A098869 * A123284 A123606 A062864 Adjacent sequences:  A131541 A131542 A131543 * A131545 A131546 A131547 KEYWORD more,nonn,base AUTHOR Shyam Sunder Gupta, Aug 26 2007 EXTENSIONS a(11)-a(14) from Lars Blomberg, Feb 02 2013 STATUS approved

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

Last modified January 20 14:40 EST 2019. Contains 319333 sequences. (Running on oeis4.)