Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A075844
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A075844 11*n^2 + 4 is a square. +0
2
0, 6, 120, 2394, 47760, 952806, 19008360, 379214394, 7565279520, 150926376006, 3010962240600, 60068318435994, 1198355406479280, 23907039811149606, 476942440816512840, 9514941776519107194, 189821893089565631040 (list; graph; listen)
OFFSET

0,2

COMMENT

Lim. n-> Inf. a(n)/a(n-1) = 10 + 3*Sqrt(11).

REFERENCES

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.

L. E. Dickson, History of the Theory of Numbers, Vol. II, Diophantine Analysis. AMS Chelsea Publishing, Providence, Rhode Island, 1999, p. 341-400.

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.

LINKS

Index entries for sequences related to linear recurrences with constant coefficients

Tanya Khovanova, Recursive Sequences

J. J. O'Connor and E. F. Robertson, Pell's Equation

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

FORMULA

a(n) = [(10+3*Sqrt(11))^n - (10-3*Sqrt(11))^n] / Sqrt(11); a(n) = 20*a(n-1) - a(n-2).

G.f.: 6x / (1 - 20x + x^2).

CROSSREFS

Equals (1/3)[A075839(n+1)-A075839(n)].

Sequence in context: A001516 A026337 A065888 this_sequence A029697 A126448 A126446

Adjacent sequences: A075841 A075842 A075843 this_sequence A075845 A075846 A075847

KEYWORD

nonn

AUTHOR

Gregory V. Richardson (omomom(AT)hotmail.com), Oct 14 2002

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 November 24 14:25 EST 2009. Contains 167438 sequences.


AT&T Labs Research