id:A145678 - OEIS Search Results

Search: id:A145678

Displaying 1-1 of 1 results found.

page 1

a(n)=21*(21*n^2-1).

+0
2

420, 1743, 3948, 7035, 11004, 15855, 21588, 28203, 35700, 44079, 53340, 63483, 74508, 86415, 99204, 112875, 127428, 142863, 159180, 176379, 194460, 213423, 233268, 253995, 275604, 298095, 321468, 345723, 370860, 396879, 423780, 451563 (list; graph; listen)

	OFFSET	`1,1`
	COMMENT	`The identity (42n^2-1)^2 - (441n^2-21) * (2n)^2 = 1 can be written` `in Pell-type form as (A158626(n))^2 - a(n) (A005843(n))^2 =1.`
	LINKS	`Vincenzo Librandi, X^2-AY^2=1` `Edward Everett Withford, Pell Equation` `Wolfram MathWorld, Pell Equation`
	CROSSREFS	`Cf. A005843, A158626` `Sequence in context: A156687 A147775 A135196 this_sequence A160372 A061125 A166784` `Adjacent sequences: A145675 A145676 A145677 this_sequence A145679 A145680 A145681`
	KEYWORD	`nonn,easy`
	AUTHOR	`Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 23 2009`
	EXTENSIONS	`Comment rewritten - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 16 2009`

page 1

Search completed in 0.002 seconds

Last modified December 10 00:48 EST 2009. Contains 170565 sequences.

AT&T Labs Research