A158593 - OEIS

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A158593

a(n)=38*n^2+1.

1, 39, 153, 343, 609, 951, 1369, 1863, 2433, 3079, 3801, 4599, 5473, 6423, 7449, 8551, 9729, 10983, 12313, 13719, 15201, 16759, 18393, 20103, 21889, 23751, 25689, 27703, 29793, 31959, 34201, 36519, 38913, 41383, 43929, 46551, 49249, 52023, 54873 (list; graph; refs; listen; history; internal format)

	OFFSET	`0,2`
	COMMENTS	`The identity (38n^2+1)^2 - (361n^2+19)(2n)^2 = 1 can be written in` `Pell-format as (a(n))^2 - A158592(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.: -(1+36x+39x^2)/(x-1)^3.`
	CROSSREFS	`Cf. A005843, A158592` `Sequence in context: A044752 A072253 A128826 * A158598 A105838 A193228` `Adjacent sequences: A158590 A158591 A158592 * A158594 A158595 A158596`
	KEYWORD	`nonn,easy`
	AUTHOR	`Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 22 2009`
	EXTENSIONS	`Comment rewritten, formula replaced by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 28 2009`

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Last modified February 15 05:45 EST 2012. Contains 205694 sequences.