A215144 a(n) = 19*n + 1.

1, 20, 39, 58, 77, 96, 115, 134, 153, 172, 191, 210, 229, 248, 267, 286, 305, 324, 343, 362, 381, 400, 419, 438, 457, 476, 495, 514, 533, 552, 571, 590, 609, 628, 647, 666, 685, 704, 723, 742, 761, 780, 799, 818, 837, 856, 875, 894, 913, 932, 951, 970, 989

Offset: 0

Author

Jeremy Gardiner, Aug 04 2012

Keywords

• nonn
• easy

Links

• Jeremy Gardiner, Table of n, a(n) for n = 0..999
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Cf. A141868, A161705.

First differences of A051873.

Programs

Magma

I:=[1,20]; [n le 2 select I[n] else 2*Self(n-1) - Self(n-2): n in [1..30]]; // G. C. Greubel, Apr 19 2018

Mathematica

Range[1, 1000, 19]
19*Range[0,60]+1 (* Harvey P. Dale, Nov 14 2014 *)
LinearRecurrence[{2,-1}, {1,20}, 50] (* G. C. Greubel, Apr 19 2018 *)

PARI

for(n=0, 50, print1(19*n + 1, ", ")) \\ G. C. Greubel, Apr 19 2018

Formula

From G. C. Greubel, Apr 19 2018: (Start)

a(n) = 2*a(n-1) - a(n-2).

G.f.: (1+18*x)/(1-x)^2.

E.g.f.: (1+19*x)*exp(x). (End)