A108173 Let beta = A058265. Sequence gives a(n) = 1 + ceiling((n-1)*beta^2).

1, 5, 8, 12, 15, 18, 22, 25, 29, 32, 35, 39, 42, 45, 49, 52, 56, 59, 62, 66, 69, 73, 76, 79, 83, 86, 89, 93, 96, 100, 103, 106, 110, 113, 117, 120, 123, 127, 130, 133, 137, 140, 144, 147, 150, 154, 157, 160, 164, 167, 171, 174, 177, 181, 184, 188, 191, 194, 198, 201

Offset

1,2

Comments

Tribonacci version of A007066 using positive real Pisot root of x^3-x^2-x-1.

Links

Table of n, a(n) for n=1..60.

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: A190773 A212452 A184915 * A346308 A214858 A186276

Adjacent sequences: A108170 A108171 A108172 * A108174 A108175 A108176

Keyword

nonn

Author

Roger L. Bagula, Jun 13 2005

Extensions

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, May 31 2007

Status

approved