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A158386 676n + 1. 2
677, 1353, 2029, 2705, 3381, 4057, 4733, 5409, 6085, 6761, 7437, 8113, 8789, 9465, 10141, 10817, 11493, 12169, 12845, 13521, 14197, 14873, 15549, 16225, 16901, 17577, 18253, 18929, 19605, 20281, 20957, 21633, 22309, 22985, 23661, 24337 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The identity (676*n+1)^2-(676*n^2+2*n)*(26)^2=1 can be written as a(n)^2-A158385(n)*(26)^2=1.

LINKS

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

Vincenzo Librandi, X^2-AY^2=1

E. J. Barbeau, Polynomial Excursions, Chapter 10: Diophantine equations (2010), pages 84-85 (row 15 in the first table at p. 85, case d(t) = t*(26^2*t+2)).

Index to sequences with linear recurrences with constant coefficients, signature (2,-1).

FORMULA

G.f.: x*(677-x)/(1-x)^2.

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

MATHEMATICA

LinearRecurrence[{2, -1}, {677, 1353}, 50]

PROG

(MAGMA) I:=[677, 1353]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]];

(PARI) a(n) = 676*n + 1.

CROSSREFS

Cf. A158385.

Sequence in context: A058450 A159893 A142755 * A031614 A031730 A205749

Adjacent sequences:  A158383 A158384 A158385 * A158387 A158388 A158389

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Mar 17 2009

STATUS

approved

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Last modified May 22 13:05 EDT 2013. Contains 225536 sequences.