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 A131544 Least power of 3 having exactly n consecutive 9's in its decimal representation. 10
 2, 34, 35, 276, 1520, 2342, 8882, 32313, 164065, 265693, 1123487, 2421341, 6250773, 9995032, 68353789, 78927182 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS No more terms < 10^8. - Bert Dobbelaere, Mar 20 2019 LINKS Table of n, a(n) for n=1..16. 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 Cf. A195269, A131552, A131551, A131550, A131549, A131548, A131547, A131546, A131545. Sequence in context: A343905 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 a(15) from Bert Dobbelaere, Mar 04 2019 a(16) from Bert Dobbelaere, Mar 20 2019 STATUS approved

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Last modified May 20 14:08 EDT 2024. Contains 372717 sequences. (Running on oeis4.)