A308197 Numbers m such that the tribonacci representation of m (A278038) ends in an even number of 0's.

1, 3, 4, 5, 8, 10, 11, 12, 13, 14, 16, 17, 18, 21, 23, 25, 27, 28, 29, 32, 34, 35, 36, 37, 38, 40, 41, 42, 44, 45, 47, 48, 49, 52, 54, 55, 56, 57, 58, 60, 61, 62, 65, 67, 69, 71, 72, 73, 76, 78, 79, 80, 82, 84, 85, 86, 89, 91, 92, 93, 94, 95, 97, 98, 99, 102, 104, 106, 108, 109, 110, 113, 115, 116, 117, 118, 119, 121

Offset

1,2

Comments

The asymptotic density of this sequence is c/(c+1) = 0.647798..., where c = 1.839286... (A058265) is the tribonacci constant. - Amiram Eldar, Mar 04 2022

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

t[1] = 1; t[2] = 2; t[3] = 4; t[n_] := t[n] = t[n - 1] + t[n - 2] + t[n - 3]; q[n_] := Module[{s = {}, m = n, k}, While[m > 0, k = 1; While[t[k] <= m, k++]; k--; AppendTo[s, k]; m -= t[k]; k = 1]; EvenQ[Min[s] - 1]]; Select[Range[0, 121], q] (* Amiram Eldar, Mar 04 2022 *)

Crossrefs

Cf. A278038, A278045, A308198, A058265.

Sequence in context: A125884 A346456 A001602 * A087012 A047366 A184776

Adjacent sequences: A308194 A308195 A308196 * A308198 A308199 A308200

Keyword

nonn,base

Author

N. J. A. Sloane, Jun 22 2019

Status

approved