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 A140044 Sequence generated from the 5/5Z addition table considered as a matrix. 2
 1, 20, 175, 2025, 19500, 200625, 1990625, 20012500, 199828125, 2000234375, 19996875000, 200004296875, 1999943359375, 20000078125000, 199998974609375, 2000001416015625, 19999981445312500, 200000025634765625, 1999999664306640625, 20000000463867187500 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Analogous sequence for Z/4Z = A095897; and for Z/3Z = A007070. a(n)/a(n-1) tends to 10. LINKS Index entries for linear recurrences with constant coefficients, signature (10,25,-250,-125,1250). FORMULA Consider the 5/5Z addition table considered as matrix X = [0,1,2,3,4; 1,2,3,4,0; 2,3,4,0,1; 3,4,0,1,2; 4,0,1,2,3]. Then a(n) = term (1,2) of X^n. G.f.: -x*(25*x^3-50*x^2+10*x+1) / ((10*x-1)*(125*x^4-25*x^2+1)). - Colin Barker, May 25 2013 EXAMPLE a(5) = 19500 since term (1,2) of X^5 = 19500. MAPLE a:= n-> (Matrix(5, (i, j)-> irem(i+j-2, 5))^n)[1, 2]: seq(a(n), n=1..25);  # Alois P. Heinz, May 25 2013 CROSSREFS Cf. A007070, A095897. Sequence in context: A047819 A163689 A342387 * A027332 A159538 A091983 Adjacent sequences:  A140041 A140042 A140043 * A140045 A140046 A140047 KEYWORD nonn,easy AUTHOR Gary W. Adamson and Roger L. Bagula, May 02 2008 EXTENSIONS Two terms corrected and more terms added by Colin Barker, May 25 2013 STATUS approved

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Last modified November 30 02:18 EST 2021. Contains 349416 sequences. (Running on oeis4.)