

A035485


Card on top of deck at nth stage of R. K. Guy's shuffling problem.


21



1, 2, 3, 1, 6, 5, 9, 1, 4, 2, 16, 10, 12, 14, 23, 16, 18, 20, 17, 27, 30, 33, 38, 10, 14, 37, 32, 6, 11, 19, 53, 37, 25, 21, 12, 34, 38, 8, 50, 48, 46, 14, 18, 23, 47, 53, 84, 52, 31, 49, 1, 51, 91, 61, 42, 79, 4, 29, 6, 49, 26, 23, 115, 4, 70, 93, 109, 11, 16, 19, 49, 18, 124, 97, 70, 10, 134, 111, 7, 38, 14, 79, 11, 129
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OFFSET

0,2


COMMENTS

At nth step, pick up top n cards and interlace them with the next n.
Here is the deck after steps 0,1,2,3,4,5:
1,2,3,4,5,6,7,...
2,1,3,4,5,6,7,...
3,2,4,1,5,6,7,...
1,3,5,2,6,4,7,8,9,...
6,1,4,3,7,5,8,2,9,10,...
It is conjectured that eventually every number appears on top of the deck.


REFERENCES

D. Gale, Mathematical Entertainments: "Careful CardShuffling and Cutting Can Create Chaos," The Mathematical Intelligencer, vol. 14, no. 1, 1992, pages 5456.
D. Gale, Tracking the Automatic Ant and Other Mathematical Explorations, A Collection of Mathematical Entertainments Columns from The Mathematical Intelligencer, Springer, 1998.


LINKS

Lars Blomberg, Table of n, a(n) for n = 0..10000
Eric Weisstein's World of Mathematics, Perfect Shuffle.


CROSSREFS

See A035491 for the array, also A035490, A035492.
Sequence in context: A110237 A189970 A076631 * A074306 A294218 A036039
Adjacent sequences: A035482 A035483 A035484 * A035486 A035487 A035488


KEYWORD

nonn,easy,nice


AUTHOR

N. J. A. Sloane, Clark Kimberling


EXTENSIONS

More terms from Jud McCranie


STATUS

approved



