A145120 - OEIS

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A145120

Numbers X such that (X^2-19)/57 is a square

38, 11438, 3454238, 1043168438, 315033414038, 95139047871038, 28731677423639438, 8676871442891239238, 2620386444075730610438, 791348029239427753113038, 238984484443863105709527038 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	LINKS	`Index to sequences with linear recurrences with constant coefficients, signature (302,-1).`
	FORMULA	`a(n+2)=302a(n+1)-a(n)` `a(n)=19{[151+20sqrt(57)]^n+[151-20sqrt(57)]^n}-(5/2)sqrt(57){[151-20sqrt(57)]^n-[151+20sqrt(57)]^n }, with n>=0 [From Paolo P. Lava (paoloplava(AT)gmail.com), Nov 25 2008]` `G.f. -38x(-1+x) / ( 1-302x+x^2 ). - R. J. Mathar, Nov 27 2011` `a(n) = 38A145123(n). - R. J. Mathar, Nov 27 2011`
	EXAMPLE	`a(1)=38 because 38^2=57*25+19`
	CROSSREFS	`Sequence in context: A055605 A173133 A096558 * A183581 A030260 A145122` `Adjacent sequences: A145117 A145118 A145119 * A145121 A145122 A145123`
	KEYWORD	`easy,nonn`
	AUTHOR	`Richard Choulet (richardchoulet(AT)yahoo.fr), Oct 02 2008`

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.