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A237346
For k in {2,3,...,9} define a sequence as follows: a(0)=0; for n>=0, a(n+1)=a(n)+1, unless a(n) ends in k, in which case a(n+1) is obtained by replacing the last digit of a(n) with the digit(s) of k^2. This is k(9).
9
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 81, 82, 83, 84, 85, 86, 87, 88, 89, 881, 882, 883, 884, 885, 886, 887, 888, 889, 8881, 8882, 8883, 8884, 8885, 8886, 8887, 8888, 8889, 88881, 88882, 88883, 88884, 88885, 88886, 88887, 88888, 88889, 888881, 888882, 888883, 888884
OFFSET
0,3
LINKS
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 11, 0, 0, 0, 0, 0, 0, 0, 0, -10).
FORMULA
G.f.: -(10*x^18 -10*x^16 -20*x^15 -30*x^14 -40*x^13 -50*x^12 -60*x^11 -70*x^10 -9*x^9 -8*x^8 -7*x^7 -6*x^6 -5*x^5 -4*x^4 -3*x^3 -2*x^2 -x) / (10*x^18 -11*x^9 +1). - Alois P. Heinz, Feb 07 2014
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Vincenzo Librandi, Feb 06 2014
EXTENSIONS
Definition by N. J. A. Sloane, Feb 07 2014
STATUS
approved