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 A079004 Least x>=3 such that F(x)==1 (mod 3^n) where F(x) denotes the x-th Fibonacci number (A000045). 4
 7, 10, 10, 34, 106, 322, 970, 2914, 8746, 26242, 78730, 236194, 708586, 2125762, 6377290, 19131874, 57395626, 172186882, 516560650, 1549681954, 4649045866, 13947137602, 41841412810, 125524238434, 376572715306, 1129718145922 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES R. L. Graham, D. E. Knuth and O. Patashnick, "Concrete Mathematics", second edition, Addison Wesley, ex. 6.59. LINKS Index entries for linear recurrences with constant coefficients, signature (4,-3). FORMULA a(1)=7, a(2)=10, a(3)=10; for n>3, a(n) = 3*a(n-1) + 4. a(n) = 4*3^(n-2)-2 for n >= 3. G.f.: 8*x^2+(23/3)*x+14/9+2/(x-1)-4/(9*(3*x-1)). - Robert Israel, Jan 15 2015 MAPLE 7, 10, seq(4*3^(n-2)-2, n=3..50); # Robert Israel, Jan 15 2015 MATHEMATICA a=2; lst={7, 10}; Do[a=a*3+4; AppendTo[lst, a], {n, 0, 5!}]; lst (* Vladimir Joseph Stephan Orlovsky, Dec 25 2008 *) PROG (PARI) a(n)=if(n<0, 0, x=3; while((fibonacci(x)-1)%(3^n)>0, x++); x) CROSSREFS Cf. A000045, A003462, A007051, A034472, A024023, A067771, A029858, A134931, A115099, A100774. Sequence in context: A225694 A247191 A317336 * A265311 A192268 A117319 Adjacent sequences:  A079001 A079002 A079003 * A079005 A079006 A079007 KEYWORD nonn,easy AUTHOR Benoit Cloitre, Feb 01 2003 EXTENSIONS Formula corrected by Robert Israel, Jan 15 2015 STATUS approved

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Last modified September 21 22:32 EDT 2020. Contains 337274 sequences. (Running on oeis4.)