A135042 a(n) = 5*(n - 1) for n >= 2; a(0) = 1, a(1) = 2.

1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, 205, 210, 215, 220, 225, 230, 235, 240, 245, 250

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (2,-1).

Formula

a(n) = 2*a(n-1) - a(n-2), n > 3. - R. J. Mathar, Apr 21 2010, corrected Sep 02 2010

G.f.: (1 + 2*x^2 + 2*x^3)/(1-x)^2. - Colin Barker, Feb 01 2012

From G. C. Greubel, Sep 18 2016: (Start)

a(n) = 5*(n - 1) for n >= 2.

E.g.f.: 5*(-1 + x)*exp(x) + 2*(3 + x). (End)

Mathematica

Join[{1, 2}, Table[5*(n-1), {n, 2, 25}]] (* G. C. Greubel, Sep 18 2016 *)

Prog

(Magma) [1, 2] cat [5*(n-1): n in [2..50]]; // Vincenzo Librandi, Sep 18 2016

Crossrefs

Cf. A008587.

Sequence in context: A105370 A173694 A190459 * A109666 A215098 A024390

Adjacent sequences: A135039 A135040 A135041 * A135043 A135044 A135045

Keyword

nonn,easy

Author

Gary W. Adamson, May 10 2008

Extensions

Offset corrected, and one 75 replaced with 65, by R. J. Mathar, Apr 21 2010

Meaningful name using formula by G. C. Greubel from Joerg Arndt, Jun 30 2023

Status

approved