Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A158592
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A158592 a(n)=19*(19*n^2+1). +0
2
19, 380, 1463, 3268, 5795, 9044, 13015, 17708, 23123, 29260, 36119, 43700, 52003, 61028, 70775, 81244, 92435, 104348, 116983, 130340, 144419, 159220, 174743, 190988, 207955, 225644, 244055, 263188, 283043, 303620, 324919, 346940, 369683 (list; graph; listen)
OFFSET

0,1

COMMENT

The identity (38*n^2+1)^2 - (361*n^2+19)*(2*n)^2 = 1 can be written in

Pell-format as (A158593(n))^2 - a(n)* (A005843(n))^2 =1.

LINKS

Vincenzo Librandi, X^2-AY^2=1

Edward Everett Withford, Pell Equation

Wolfram MathWorld, Pell Equation

FORMULA

a(n)= 3*a(n-1) -3*a(n-2) +a(n-3). G.f.: -19*(1+17*x+20*x^2)/(x-1)^3.

CROSSREFS

Sequence in context: A041686 A023283 A075839 this_sequence A072359 A094737 A009075

Adjacent sequences: A158589 A158590 A158591 this_sequence A158593 A158594 A158595

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 22 2009

EXTENSIONS

Comment rewritten, formula replaced by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 28 2009

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 3 22:15 EST 2009. Contains 170310 sequences.


AT&T Labs Research