id:A158680 - OEIS Search Results

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a(n)=62*n^2-1.

+0
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61, 247, 557, 991, 1549, 2231, 3037, 3967, 5021, 6199, 7501, 8927, 10477, 12151, 13949, 15871, 17917, 20087, 22381, 24799, 27341, 30007, 32797, 35711, 38749, 41911, 45197, 48607, 52141, 55799, 59581, 63487, 67517, 71671, 75949, 80351 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`The identity (62n^2-1)^2 - (961n^2-31) * (2n)^2 = 1 can be written as` `the Pell equation (a(n))^2 - A158679(n) (A005843(n))^2 = 1.`
	LINKS	`Vincenzo Librandi, X^2-AY^2=1` `Edward Everett Withford, Pell Equation` `Wolfram MathWorld, Pell Equation`
	FORMULA	`a(n)= 3a(n-1) -3a(n-2) +a(n-3). G.f.: x(-61-64x+x^2)/(x-1)^3.`
	CROSSREFS	`Cf. A005843, A158679` `Sequence in context: A142267 A034863 A158673 this_sequence A152413 A029815 A142424` `Adjacent sequences: A158677 A158678 A158679 this_sequence A158681 A158682 A158683`
	KEYWORD	`nonn,easy`
	AUTHOR	`Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 24 2009`
	EXTENSIONS	`Comment rewritten and formula replaced by R. J. Mathar, (mathar(AT)strw.leidenuniv.nl), Oct 22 2009`

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Last modified November 30 13:13 EST 2009. Contains 167758 sequences.

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