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

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 59th year, we have over 358,000 sequences, and we’ve crossed 10,300 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A102483 Numbers k such that 2^k contains no zeros in base 3. 18
 0, 1, 2, 3, 4, 15 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS I conjectured in 1973 that there are no further terms. This question is still open. A104320(a(n)) = 0. - Reinhard Zumkeller, Mar 01 2005 No other terms less than 200000. - Robert G. Wilson v, Dec 06 2005 a(7) > 10^7. - Martin Ehrenstein, Jul 27 2021 If it exists, a(7) > 10^21. - Robert Saye, Mar 23 2022 LINKS Robert I. Saye, On two conjectures concerning the ternary digits of powers of two, J. Integer Seq. 25 (2022) Article 22.3.4. N. J. A. Sloane, The persistence of a number, J. Recreational Math., 6 (1973), 97-98. Eric Weisstein's World of Mathematics, Ternary MATHEMATICA Select[ Range@1000, FreeQ[ IntegerDigits[2^#, 3], 0] &] (* Robert G. Wilson v, Dec 06 2005 *) PROG (PARI) for (n=0, 100, if (vecmin(digits(2^n, 3)), print1(n, ", "))) \\ Michel Marcus, Mar 25 2015 CROSSREFS Cf. A007377, A004642, A346497. Sequence in context: A295756 A140047 A297840 * A134916 A085100 A337117 Adjacent sequences: A102480 A102481 A102482 * A102484 A102485 A102486 KEYWORD nonn,base,hard AUTHOR N. J. A. Sloane, Feb 25 2005 STATUS approved

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.

Last modified December 7 01:51 EST 2022. Contains 358649 sequences. (Running on oeis4.)