A323454 Minimal number of steps to reach n from 1 using "Choix de Bruxelles", version 2 (cf. A323460), or -1 if n cannot be reached.
0, 1, 11, 2, -1, 10, 9, 3, 9, -1, 10, 9, 5, 8, -1, 4, 7, 8, 8, -1, 10, 9, 6, 8, -1, 5, 8, 7, 9, -1, 6, 5, 10, 6, -1, 9, 9, 7, 9, -1, 11, 10, 7, 9, -1, 6, 9, 8, 10, -1, 7, 6, 7, 7, -1, 6, 7, 8, 8, -1, 7, 6, 11, 6, -1, 10, 10, 7, 10, -1, 8, 8, 9, 8, -1, 8, 11, 8
Offset: 1
Examples
Examples of optimal ways to reach 1,2,3,...: 1 1, 2 1, 2, 4, 8, 16, 112, 56, 28, 14, 12, 6, 3 1, 2, 4 5 cannot be reached, ends in 0 or 5 1, 2, 4, 8, 16, 112, 56, 28, 14, 12, 6 1, 2, 4, 8, 16, 112, 56, 28, 14, 7 1, 2, 4, 8, 1, 2, 4, 8, 16, 112, 56, 28, 18, 9. 10 cannot be reached, ends in 0 or 5 1, 2, 4, 8, 16, 112, 56, 28, 24, 22, 11 1, 2, 4, 8, 16, 112, 56, 28, 14, 12 1, 2, 4, 8, 16, 13 1, 2, 4, 8, 16, 112, 56, 28, 14 15 cannot be reached, ends in 0 or 5 1, 2, 4, 8, 16 1, 2, 4, 8, 16, 32, 34, 17 1, 2, 4, 8, 16, 112, 56, 28, 18 1, 2, 4, 8, 16, 32, 34, 38, 19 20 cannot be reached, ends in 0 or 5 ...
Links
- Rémy Sigrist, Table of n, a(n) for n = 1..10000
- 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.
- Brady Haran and N. J. A. Sloane, The Brussels Choice, Numberphile video (2020)
- N. J. A. Sloane, Coordination Sequences, Planing Numbers, and Other Recent Sequences (II), Experimental Mathematics Seminar, Rutgers University, Jan 31 2019, Part I, Part 2, Slides. (Mentions this sequence)
Crossrefs
Extensions
More terms from Rémy Sigrist, Jan 15 2019
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