login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A307169 First class of all proper positive solutions y1(n) = a(n) of the Pell equation x^2 - 7*y^2 = 9. 3
4, 65, 1036, 16511, 263140, 4193729, 66836524, 1065190655, 16976213956, 270554232641, 4311891508300, 68719709900159, 1095203466894244, 17454535760407745, 278177368699629676, 4433383363433667071, 70655956446239043460, 1126061919776391028289, 17946334759976017409164 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The corresponding x1 solutions are given in A307168.

For details see A307168.

LINKS

Table of n, a(n) for n=1..19.

Index entries for sequences related to Chebyshev polynomials.

Index entries for linear recurrences with constant coefficients, signature (16,-1).

FORMULA

G.f.: x*(4 + x)/(1 - 16*x + x^2).

a(n) = -S(n, 16) + 20*S(n-1, 16) for n >= 1, with S(n,16) = A077412(n).

a(n) = sqrt((A307168(n)^2 - 9)/7) for n >= 1.

CROSSREFS

Cf. A077412, A307168.

Sequence in context: A041119 A278547 A293562 * A307185 A206500 A266520

Adjacent sequences:  A307166 A307167 A307168 * A307170 A307171 A307172

KEYWORD

nonn,easy

AUTHOR

Wolfdieter Lang, Mar 27 2019

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 22 18:55 EST 2019. Contains 329410 sequences. (Running on oeis4.)