A323453 - OEIS

%I #29 Jul 13 2020 12:19:49

%S 1,2,4,8,16,112,224,512,4416,44112,88224,816448,8164416,81644112,

%T 811288224,8112816448,81128164416,811281644112,8112811288224,

%U 81128112816448,811281128164416,8112811281644112,81128112811288224,811281128112816448,8118112281128164416,81181122811281644112

%N Largest number that can be obtained by starting with 1 and applying "Choix de Bruxelles (version 2)" (see A323460) n times.

%C Also, largest number that can be obtained by starting with 1 and applying the original "Choix de Bruxelles" version 1 operation (as defined in A323286) at most n times.

%C a(n) is the largest number that can be obtained by applying Choix de Bruxelles (version 2) to all the numbers that can be reached from 1 by applying it n-1 times.

%C a(n+1) >= A323460(a(n)) (but equality does not always hold). See A307635. - _Rémy Sigrist_, Jan 15 2019

%H Eric Angelini, Lars Blomberg, Charlie Neder, Remy Sigrist, and N. J. A. Sloane, <a href="http://arxiv.org/abs/1902.01444">"Choix de Bruxelles": A New Operation on Positive Integers</a>, arXiv:1902.01444, Feb 2019; Fib. Quart. 57:3 (2019), 195-200.

%F a(n+4) = decimal concatenation of 8112 and a(n) for n >= 10.

%e After applying Choix de Bruxelles (version 2) 4 times to 1, we have the numbers {1,2,4,8,16}. Applying it a fifth time we get the additional numbers {13,26,32,112}, so a(5) = 112.

%Y Cf. A323286-A323289, A323460, A307635.

%K nonn,base

%O 0,2

%A _N. J. A. Sloane_, Jan 15 2019

%E a(9)-a(16) from _Rémy Sigrist_, Jan 15 2019. Further terms from _N. J. A. Sloane_, May 01 2019