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 A041699 Denominators of continued fraction convergents to sqrt(369). 2
 1, 4, 5, 19, 43, 320, 1323, 9581, 20485, 71036, 91521, 437120, 16702081, 67245444, 83947525, 319088019, 722123563, 5373952960, 22217935403, 160899500781, 344016936965, 1192950311676, 1536967248641, 7340819306240, 280488100885761, 1129293222849284 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 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, 16793602, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1). FORMULA G.f.: (1 +4*x +5*x^2 +19*x^3 +43*x^4 +320*x^5 +1323*x^6 +9581*x^7 +20485*x^8 +71036*x^9 +91521*x^10 +437120*x^11 -91521*x^12 +71036*x^13 -20485*x^14 +9581*x^15 -1323*x^16 +320*x^17 -43*x^18 +19*x^19 -5*x^20 +4*x^21 -x^22)/(1 -16793602*x^12 +x^24). - Vincenzo Librandi, Dec 23 2013 a(n) = 16793602*a(n-12) - a(n-24) for n>23 Vincenzo Librandi, Dec 23 2013 MATHEMATICA Denominator[Convergents[Sqrt[369], 30]] (* or *) CoefficientList[Series[(1 + 4 x + 5 x^2 + 19 x^3 + 43 x^4 + 320 x^5 + 1323 x^6 + 9581 x^7 + 20485 x^8 + 71036 x^9 + 91521 x^10 + 437120 x^11 - 91521 x^12 + 71036 x^13 - 20485 x^14 + 9581 x^15 - 1323 x^16 + 320 x^17 - 43 x^18 + 19 x^19 - 5 x^20 + 4 x^21 - x^22)/(1 - 16793602 x^12 + x^24), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 23 2013 *) CROSSREFS Cf. A041698. Sequence in context: A042085 A136211 A041036 * A154704 A047023 A032319 Adjacent sequences:  A041696 A041697 A041698 * A041700 A041701 A041702 KEYWORD nonn,frac,easy AUTHOR EXTENSIONS More terms from Vincenzo Librandi, Dec 23 2013 STATUS approved

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