A237345 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(8).

0, 1, 2, 3, 4, 5, 6, 7, 8, 64, 65, 66, 67, 68, 664, 665, 666, 667, 668, 6664, 6665, 6666, 6667, 6668, 66664, 66665, 66666, 66667, 66668, 666664, 666665, 666666, 666667, 666668, 6666664, 6666665, 6666666, 6666667, 6666668, 66666664, 66666665, 66666666

Offset

0,3

Links

Table of n, a(n) for n=0..41.

Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 11, 0, 0, 0, 0, -10).

Formula

G.f.: -(10*x^13 +10*x^12 +10*x^11 +10*x^10 +20*x^9 -25*x^8 -15*x^7 -5*x^6 +5*x^5 +4*x^4 +3*x^3 +2*x^2+x)/(-10*x^10+11*x^5-1). - Alois P. Heinz, Feb 07 2014

Crossrefs

Cf. A235498, A235499, A237341 - A237346.

Sequence in context: A024653 A024654 A004859 * A024655 A250264 A273476

Adjacent sequences: A237342 A237343 A237344 * A237346 A237347 A237348

Keyword

nonn,base,easy

Author

Vincenzo Librandi, Feb 06 2014

Extensions

Definition by N. J. A. Sloane, Feb 07 2014

Status

approved