A157609 a(n) = 2662*n - 22.

2640, 5302, 7964, 10626, 13288, 15950, 18612, 21274, 23936, 26598, 29260, 31922, 34584, 37246, 39908, 42570, 45232, 47894, 50556, 53218, 55880, 58542, 61204, 63866, 66528, 69190, 71852, 74514, 77176, 79838, 82500, 85162, 87824, 90486

Offset

1,1

Comments

The identity (29282*n^2-484*n+1)^2-(121*n^2-2*n)*(2662*n-22)^2=1 can be written as A157610(n)^2-A157040(n)*a(n)^2=1.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

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

Formula

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

G.f: x*(2640+22*x)/(x-1)^2.

Mathematica

LinearRecurrence[{2, -1}, {2640, 5302}, 40]

Prog

(Magma) I:=[2640, 5302]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..40]];
(PARI) a(n) = 2662*n - 22

Crossrefs

Sequence in context: A273184 A252579 A253040 * A249462 A257183 A257190

Adjacent sequences: A157606 A157607 A157608 * A157610 A157611 A157612

Keyword

nonn,easy

Author

Vincenzo Librandi, Mar 03 2009

Status

approved