A108171 - OEIS

A108171

Tribonacci version of A076662 using beta positive real Pisot root of x^3 - x^2 - x - 1.

4, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3, 4, 3, 3, 4, 3, 4, 3, 3

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OFFSET

0,1

COMMENTS

Three part composition of sequence based on the Fibonacci substitution twos order.

LINKS

Table of n, a(n) for n=0..98.

FORMULA

b(n) = 1 + ceiling((n-1)*beta); a(n) = b(n) - b(n-1).

MATHEMATICA

NSolve[x^3 - x^2 - x - 1 = 0, x] beta = 1.8392867552141612 a[n_] = 1 + Ceiling[(n - 1)*beta^2] (* A007066 like*) aa = Table[a[n], {n, 1, 100}] (* A076662-like *) b = Table[a[n] - a[n - 1], {n, 2, Length[aa]}] F[1] = 2; F[n_] := F[n] = F[n - 1] + b[[n]] (* A000195-like *) c = Table[F[n], {n, 1, Length[b] - 1}]

CROSSREFS

Cf. A007066, A076662, A000195.

Sequence in context: A367439 A367126 A136627 * A231475 A106055 A171783

Adjacent sequences: A108168 A108169 A108170 * A108172 A108173 A108174

KEYWORD

nonn,uned

AUTHOR

Roger L. Bagula, Jun 13 2005

STATUS

approved