A184882 a(n)=1-4*n-4*n^2.

1, -7, -23, -47, -79, -119, -167, -223, -287, -359, -439, -527, -623, -727, -839, -959, -1087, -1223, -1367, -1519, -1679, -1847, -2023, -2207, -2399, -2599, -2807, -3023, -3247, -3479, -3719, -3967, -4223, -4487, -4759, -5039, -5327, -5623

Offset: 0

Author

Paul Barry, Jan 24 2011

Keywords

• sign
• easy

Comments

Hankel transform of A184881.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

Programs

Magma

[1-4*n-4*n^2: n in [0..60]]; // Vincenzo Librandi, Feb 23 2014

Mathematica

Table[1-4n-4n^2,{n,0,50}] (* or *) LinearRecurrence[{3,-3,1},{1,-7,-23},50] (* Harvey P. Dale, Feb 21 2014 *)

PARI

a(n)=1-4*n-4*n^2 \\ Charles R Greathouse IV, Jun 17 2017

Formula

G.f.: (1-10*x+x^2)/(1-x)^3.

a(n)=+3*a(n-1)-3*a(n-2)+1*a(n-3) for n>=3.

a(0)=1, a(n)=a(n-1)-8*n. - Vincenzo Librandi, Jan 25 2011