A119413 a(n) = 16*n - 12.

4, 20, 36, 52, 68, 84, 100, 116, 132, 148, 164, 180, 196, 212, 228, 244, 260, 276, 292, 308, 324, 340, 356, 372, 388, 404, 420, 436, 452, 468, 484, 500, 516, 532, 548, 564, 580, 596, 612, 628, 644, 660, 676, 692, 708, 724, 740, 756, 772, 788, 804, 820, 836

Offset: 1

Author

Jorge Coveiro, Jul 26 2006

Keywords

• nonn
• less
• easy

Comments

General form: (q*n+1)*q: q=2: A016825, q=3: A017197, q=4: A119413, ... . - Vladimir Joseph Stephan Orlovsky, Feb 16 2009

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..5000
• Tanya Khovanova, Recursive Sequences.
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

Cf. A044446, A085805, A016825, A017197, A119413.

Cf. A016813, A017089.

Programs

Magma

[16*n-12: n in [1..60]]; // Vincenzo Librandi, Jul 23 2011

Mathematica

Range[4, 1000, 16] (* Vladimir Joseph Stephan Orlovsky, May 31 2011 *)

PARI

for(x=1,100,print1(16*x-12,", "))

Formula

O.g.f.: 4*x*(1+3*x)/(1-x)^2. - R. J. Mathar, Aug 08 2008

From Elmo R. Oliveira, Apr 03 2025: (Start)

E.g.f.: 4*(exp(x)*(4*x - 3) + 3).

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

a(n) = 4*A016813(n-1) = 2*A017089(n-1). (End)