A323453 Largest number that can be obtained by starting with 1 and applying "Choix de Bruxelles (version 2)" (see A323460) n times.

1, 2, 4, 8, 16, 112, 224, 512, 4416, 44112, 88224, 816448, 8164416, 81644112, 811288224, 8112816448, 81128164416, 811281644112, 8112811288224, 81128112816448, 811281128164416, 8112811281644112, 81128112811288224, 811281128112816448, 8118112281128164416, 81181122811281644112

Offset: 0

Author

N. J. A. Sloane, Jan 15 2019

Keywords

• nonn
• base

Comments

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.

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.

a(n+1) >= A323460(a(n)) (but equality does not always hold). See A307635. - Rémy Sigrist, Jan 15 2019

Examples

			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.
		

Links

• Eric Angelini, Lars Blomberg, Charlie Neder, Remy Sigrist, and N. J. A. Sloane, "Choix de Bruxelles": A New Operation on Positive Integers, arXiv:1902.01444, Feb 2019; Fib. Quart. 57:3 (2019), 195-200.
• Eric Angelini, Lars Blomberg, Charlie Neder, Remy Sigrist, and N. J. A. Sloane,, "Choix de Bruxelles": A New Operation on Positive Integers, Local copy.

Crossrefs

Cf. A323286-A323289, A323460, A307635.

Formula

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

Extensions

a(9)-a(16) from Rémy Sigrist, Jan 15 2019. Further terms from N. J. A. Sloane, May 01 2019