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 A042161 Denominators of continued fraction convergents to sqrt(605). 2
 1, 1, 2, 5, 57, 62, 553, 615, 7318, 15251, 22569, 37820, 1837929, 1875749, 3713678, 9303105, 106047833, 115350938, 1028855337, 1144206275, 13615124362, 28374454999, 41989579361, 70364034360, 3419463228641, 3489827263001, 6909290491642, 17308408246285 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1860498, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1). FORMULA G.f.: -(x^22 -x^21 +2*x^20 -5*x^19 +57*x^18 -62*x^17 +553*x^16 -615*x^15 +7318*x^14 -15251*x^13 +22569*x^12 -37820*x^11 -22569*x^10 -15251*x^9 -7318*x^8 -615*x^7 -553*x^6 -62*x^5 -57*x^4 -5*x^3 -2*x^2 -x -1) / ((x^4 -11*x^2 -1)*(x^4 +11*x^2 -1)*(x^8 -11*x^6 +122*x^4 +11*x^2 +1)*(x^8 +11*x^6 +122*x^4 -11*x^2 +1)). - Colin Barker, Dec 02 2013 a(n) = 1860498*a(n-12) - a(n-24) for n>23. - Vincenzo Librandi, Jan 16 2014 MATHEMATICA Denominator[Convergents[Sqrt[605], 30]] (* Vincenzo Librandi, Jan 16 2014_ *) CROSSREFS Cf. A042160, A040580. Sequence in context: A006525 A254406 A260654 * A176142 A101151 A138788 Adjacent sequences:  A042158 A042159 A042160 * A042162 A042163 A042164 KEYWORD nonn,frac,easy AUTHOR EXTENSIONS More terms from Colin Barker, Dec 02 2013 STATUS approved

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