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

Author

N. J. A. Sloane, Jun 22 2019

Keywords

• nonn
• base

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

Crossrefs

Cf. A278038, A278045, A308198, A058265.

Programs

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 *)