A035501 - OEIS

%I #15 Aug 11 2022 14:48:28

%S 0,1,2,4,6,10,14,19,20,21,22,30,46,52,62,72,76,85,94,120,126,144,147,

%T 169,174,190,216,221,241,251,254,273,281,289,292,300,301,305,308,323,

%U 338,341,379,382,399,421,429,447,448,449,473,479,490,509,510,544,561,583,588,615,632,651,686,715,726,764

%N Shuffles at which new record high cards appear on top of deck in Guy's shuffling problem A035485.

%D D. Gale, Mathematical Entertainments: "Careful Card-Shuffling and Cutting Can Create Chaos," Mathematical Intelligencer, vol. 14, no. 1, 1992, pages 54-56.

%D D. Gale, Tracking the Automatic Ant and Other Mathematical Explorations, A Collection of Mathematical Entertainments Columns from The Mathematical Intelligencer, Springer, 1998.

%o (Python)

%o from itertools import count, islice

%o def agen(): # generator of terms

%o     deck = []; record = 1; yield 0

%o     for n in count(1):

%o         deck += [2*n-1, 2*n]

%o         first, next = deck[:n], deck[n:2*n]

%o         deck[0:2*n:2], deck[1:2*n:2] = next, first

%o         if deck[0] > record: record = deck[0]; yield n

%o print(list(islice(agen(), 66))) # _Michael S. Branicky_, Aug 11 2022

%Y Cf. A035485, A035493, A035494, A035501.

%K nonn

%O 1,3

%A _N. J. A. Sloane_, _Wouter Meeussen_

%E More terms from _Jud McCranie_