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A100601
Denominator of the best rational approximation to the decimal representation of the digital roots of m^n, m=1,2,..
2
9, 1001, 50, 333, 1001, 100, 333, 11, 5, 9, 1001, 50, 333, 1001, 100, 333, 11, 5, 9, 1001, 50, 333, 1001, 100, 333, 11, 5, 9, 1001, 50, 333, 1001, 100, 333, 11, 5, 9, 1001, 50, 333, 1001, 100, 333, 11, 5, 9, 1001, 50, 333, 1001, 100, 333, 11, 5, 9, 1001, 50
OFFSET
1,1
COMMENTS
Sequence has period 9. - Nathaniel Johnston, May 05 2011
FORMULA
The digital root of a number m > 0, is d = m mod 9 if d > 0 else d = 9.
G.f.: -x*(5*x^8+11*x^7+333*x^6+100*x^5+1001*x^4+333*x^3+50*x^2+1001*x+9) / ((x-1)*(x^2+x+1)*(x^6+x^3+1)). - Colin Barker, Jun 23 2014
a(n) = a(n-9). - Wesley Ivan Hurt, Oct 18 2021
EXAMPLE
Digital roots of 4^n = 1,4,7,1,4,7,1,4,7,1,4,7,.. 49/333 = 0.147147147147147147147147147147147,.. 333 is the 4th term in the sequence.
PROG
(PARI) f(n, m) = for(x=0, n, print1(droot(m^x)", ")) droot(n) = \ the digital root of a number. { local(x); x= n%9; if(x>0, return(x), return(9)) }
(PARI) Vec(-x*(5*x^8+11*x^7+333*x^6+100*x^5+1001*x^4+333*x^3+50*x^2+1001*x+9) / ((x-1)*(x^2+x+1)*(x^6+x^3+1)) + O(x^100)) \\ Colin Barker, Jun 23 2014
CROSSREFS
Sequence in context: A307324 A327435 A350967 * A260029 A266321 A228293
KEYWORD
base,frac,easy,nonn
AUTHOR
Cino Hilliard, Jan 02 2005
EXTENSIONS
Offset corrected by Nathaniel Johnston, May 05 2011
STATUS
approved