A016934 a(n) = (6*n + 2)^2.

4, 64, 196, 400, 676, 1024, 1444, 1936, 2500, 3136, 3844, 4624, 5476, 6400, 7396, 8464, 9604, 10816, 12100, 13456, 14884, 16384, 17956, 19600, 21316, 23104, 24964, 26896, 28900, 30976, 33124, 35344, 37636, 40000, 42436, 44944, 47524, 50176, 52900, 55696, 58564

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..2000

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Formula

Sum_{n>=0} 1/a(n) = A086728. - Amiram Eldar, Nov 16 2020

From Stefano Spezia, Feb 21 2025: (Start)

G.f.: 4*(1 + 13*x + 4*x^2)/(1 - x)^3.

E.g.f.: 4*exp(x)*(1 + 15*x + 9*x^2). (End)

Mathematica

(6*Range[0, 40]+2)^2 (* or *) LinearRecurrence[{3, -3, 1}, {4, 64, 196}, 40] (* Harvey P. Dale, Nov 22 2013 *)

Prog

(Magma) [(6*n+2)^2: n in [0..50]]; // Vincenzo Librandi, May 04 2011
(PARI) a(n)=(6*n+2)^2 \\ Charles R Greathouse IV, Jun 17 2017

Crossrefs

Cf. A016922, A016933, A086728.

Sequence in context: A210935 A090561 A273375 * A260182 A056229 A062271

Adjacent sequences: A016931 A016932 A016933 * A016935 A016936 A016937

Keyword

nonn,easy

Author

N. J. A. Sloane

Status

approved