login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A174746 x-values in the solution to x^2-31*y^2=1. 2
1, 1520, 4620799, 14047227440, 42703566796801, 129818829015047600, 394649197502177907199, 1199733430587791822837360, 3647189234337689639247667201, 11087454072653145915521085453680 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The corresponding values of y of this Pell equation are in A174771.
LINKS
FORMULA
a(n) = 3040*a(n-1)-a(n-2) with a(1)=1, a(2)=1520.
G.f.: x*(1-1520*x)/(1-3040*x+x^2).
MATHEMATICA
LinearRecurrence[{3040, -1}, {1, 1520}, 30]
PROG
(Magma) I:=[1, 1520]; [n le 2 select I[n] else 3040*Self(n-1)-Self(n-2): n in [1..20]];
CROSSREFS
Cf. A174771.
Sequence in context: A203386 A157375 A331659 * A074906 A307745 A025413
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 12 2010
STATUS
approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)