Search: id:A075870 Results 1-1 of 1 results found. %I A075870 %S A075870 2,10,58,338,1970,11482,66922,390050,2273378,13250218,77227930, %T A075870 450117362,2623476242,15290740090,89120964298,519435045698, %U A075870 3027489309890,17645500813642,102845515571962,599427592618130 %N A075870 2*n^2 - 4 is a square. %C A075870 Lim. n-> Inf. a(n)/a(n-1) = 3 + 2*Sqrt(2). %C A075870 Also gives solutions to the equation x^2-2 = floor(x*r*floor(x/r)) where r=sqrt(2) - Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 14 2004 %C A075870 The upper intermediate convergents to 2^(1/2) beginning with 10/7, 58/ 41, 338/239, 1970/1393 form a strictly decreasing sequence; essentially, numerators=A075870, denominators=A002315. - Clark Kimberling (ck6(AT)evansville.edu), Aug 27 2008 %D A075870 A. H. Beiler, "The Pellian", ch. 22 in Recreations in the Theory of Numbers: The Queen of Mathematics Entertains. Dover, New York, New York, pp. 248-268, 1966. %D A075870 L. E. Dickson, History of the Theory of Numbers, Vol. II, Diophantine Analysis. AMS Chelsea Publishing, Providence, Rhode Island, 1999, p. 341-400. %D A075870 Peter G. L. Dirichlet, Lectures on Number Theory (History of Mathematics Source Series, V. 16); American Mathematical Society, Providence, Rhode Island, 1999, p. 139-147. %H A075870 Index entries for sequences related to linear recurrences with constant coefficients %H A075870 Tanya Khovanova, Recursive Sequences %H A075870 J. J. O'Connor and E. F. Robertson, Pell's Equation %H A075870 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %F A075870 a(n) = 1/sqrt(2)*((1+sqrt(2))^(2*n-1)-(1-sqrt(2))^(2*n-1)) = 6*a(n-1) - a(n-2) %F A075870 G.f.: 2x(1-x)/(1-6x+x^2). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 17 2008] %Y A075870 Cf. 2*A001653. %Y A075870 Sequence in context: A000172 A097971 A093303 this_sequence A074608 A086871 A108450 %Y A075870 Adjacent sequences: A075867 A075868 A075869 this_sequence A075871 A075872 A075873 %K A075870 nonn %O A075870 1,1 %A A075870 Gregory V. Richardson (omomom(AT)hotmail.com), Oct 16 2002 Search completed in 0.001 seconds