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A158057 a(n)=16*n+1 (n>0) +0
11
17, 33, 49, 65, 81, 97, 113, 129, 145, 161, 177, 193, 209, 225, 241, 257, 273, 289, 305, 321, 337, 353, 369, 385, 401, 417, 433, 449, 465, 481, 497, 513, 529, 545, 561, 577, 593, 609, 625, 641, 657, 673, 689, 705, 721 (list; graph; listen)
OFFSET

1,1

COMMENT

If A=[A158056] 16*n.^2+2*n (n>0, 18, 68, 150,., ,.,); Y=[A010709] 4 (4,4,4, ,..,); X=[A158057] 16*n+1 (n>0, 17, 33, 49, ,. .,), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 17^2-18*4^2=1; 33^2-68*4^2=1; 49^2-150*4^2=1.

LINKS

Edward Everett Withford, Pell Equation

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

Wolfram MathWorld, Pell Equation

FORMULA

a(n)=16*n+1 (n>0)

EXAMPLE

For n=1, a(1)=17; n=2, a(2)=33; n=3, a(3)=49

CROSSREFS

Cf. A158056, A010709

A161700, A005408, A016813, A016921, A017281, A017533, A161705, A161709, A161714, A128470. [From Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 17 2009]

Sequence in context: A138393 A044062 A044443 this_sequence A116523 A135637 A040272

Adjacent sequences: A158054 A158055 A158056 this_sequence A158058 A158059 A158060

KEYWORD

nonn

AUTHOR

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 12 2009

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Last modified November 24 23:16 EST 2009. Contains 167481 sequences.


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