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A003100
Decimal Gray code for n.
(Formerly M0486)
9
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 79, 78, 77
OFFSET
0,3
COMMENTS
This permutation of the nonnegative integers is not self-inverse, as previously claimed. The first exception is a(100) = 190, but a(190) = 109. - Franklin T. Adams-Watters, Mar 05 2010
a(n) = A118757(n) for n<=100, = a(100)=A118757(100)=190, but a(101)=191, A118757(101)=180. - Reinhard Zumkeller, May 01 2006
REFERENCES
M. Gardner, Knotted Doughnuts and Other Mathematical Entertainments. Freeman, NY, 1986, p. 18.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Franklin T. Adams-Watters, Table of n, a(n) for n = 0..10000
A. J. Cole, Cyclic progressive number systems, Math. Gaz., 50 (1966), 122-131.
A. J. Cole, Cyclic progressive number systems, Math. Gaz., 50 (1966), 122-131. [Annotated scanned copy]
D. E. Knuth, Gray Codes (Vol. 4 of TAOCP)
MAPLE
A003100 :=proc(n)
local s, i:
s:=[op(convert(n, base, 10)), 0]:
add(piecewise(s[i+1] mod 2=0, s[i], 9-s[i])*10^(i-1), i=1..nops(s)-1) :
end proc:
seq(A003100(j), j=0..100); # Pab Ter, Oct 14 2005
CROSSREFS
Inverse is A174025.
Sequence in context: A259046 A261725 A261729 * A118757 A118758 A174025
KEYWORD
nonn,base,easy,look
EXTENSIONS
More terms from Pab Ter (pabrlos2(AT)yahoo.com), Oct 14 2005
Incorrect comment replaced by Franklin T. Adams-Watters, Mar 05 2010
STATUS
approved