A139620 a(n) = 190*n + 20.

20, 210, 400, 590, 780, 970, 1160, 1350, 1540, 1730, 1920, 2110, 2300, 2490, 2680, 2870, 3060, 3250, 3440, 3630, 3820, 4010, 4200, 4390, 4580, 4770, 4960, 5150, 5340, 5530, 5720, 5910, 6100, 6290, 6480, 6670, 6860, 7050, 7240, 7430

Offset

0,1

Comments

Numbers of the 20th column of positive numbers in the square array of nonnegative and polygonal numbers A139600. Also, numbers of the 20th column in the square array A057145.

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..5000

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

Formula

From Elmo R. Oliveira, Apr 08 2024: (Start)

G.f.: 10*(2+17*x)/(x-1)^2.

E.g.f.: 10*exp(x)*(2 + 19*x).

a(n) = 10*(A008601(n) + 2).

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

Mathematica

190*Range[0, 40]+20 (* or *) LinearRecurrence[{2, -1}, {20, 210}, 40] (* Harvey P. Dale, Feb 04 2019 *)

Prog

(Magma) [10*(19*n + 2): n in [0..50]]; // Vincenzo Librandi, Jul 23 2011
(PARI) a(n)=190*n+20 \\ Charles R Greathouse IV, Oct 05 2011

Crossrefs

Cf. A008601, A057145, A139600.

Sequence in context: A162359 A161880 A074668 * A094311 A353895 A353884

Adjacent sequences: A139617 A139618 A139619 * A139621 A139622 A139623

Keyword

easy,nonn,changed

Author

Omar E. Pol, May 21 2008

Status

approved