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A079003
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Least x>=3 such that F(x)==-1 (mod 3^n) where F(x) denote the x-th Fibonacci number (A000045).
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0
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3, 6, 14, 38, 110, 326, 974, 2918, 8750, 26246, 78734, 236198, 708590, 2125766, 6377294, 19131878, 57395630, 172186886, 516560654, 1549681958, 4649045870, 13947137606, 41841412814, 125524238438, 376572715310, 1129718145926
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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REFERENCES
| R. L. Graham, D. E. Knuth and O. Patashnick, "Concrete Mathematics", second edition, Addison Wesley, ex.6.59
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FORMULA
| a(1)=3; for n>1, a(n)=3*a(n-1)-4; a(n)=4*3^(n-1)+2
Empirical G.f.: x*(3-6*x-x^2)/((1-x)*(1-3*x)). [Colin Barker, Jan 16 2012]
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PROG
| (PARI) a(n)=if(n<0, 0, x=3; while((fibonacci(x)+1)%(3^n)>0, x++); x)
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CROSSREFS
| Sequence in context: A197461 A100446 A106395 * A099966 A101162 A059741
Adjacent sequences: A079000 A079001 A079002 * A079004 A079005 A079006
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KEYWORD
| nonn
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AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 01 2003
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