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

Author

Gary W. Adamson, May 10 2008

Keywords

• nonn
• easy

Links

• G. C. Greubel, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Cf. A008587.

Programs

Magma

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

Mathematica

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

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)

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