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!)
A156844 279841n^2 - 394634n + 139128. 4
24335, 469224, 1473795, 3038048, 5161983, 7845600, 11088899, 14891880, 19254543, 24176888, 29658915, 35700624, 42302015, 49463088, 57183843, 65464280, 74304399, 83704200, 93663683, 104182848, 115261695, 126900224 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
The identity (279841*n^2-394634*n+139128)^2-(529*n^2-746*n+263)*(12167*n-8579)^2=1 can be written as a(n)^2-A156842(n)*A156845(n)^2=1.
LINKS
FORMULA
a(n) = 3*a(n-1) -3*a(n-2) +a(n-3).
G.f.: x*(-24335-396219*x-139128*x^2)/(x-1)^3.
MATHEMATICA
LinearRecurrence[{3, -3, 1}, {24335, 469224, 1473795}, 40]
Table[279841n^2-394634n+139128, {n, 30}] (* Harvey P. Dale, Mar 02 2021 *)
PROG
(Magma) I:=[24335, 469224, 1473795]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..40]];
(PARI) a(n)=279841*n^2-394634*n+139128 \\ Charles R Greathouse IV, Dec 23 2011
CROSSREFS
Sequence in context: A294856 A025041 A156843 * A174754 A206682 A083621
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 17 2009
EXTENSIONS
Edited by Charles R Greathouse IV, Jul 25 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 February 29 02:52 EST 2024. Contains 370401 sequences. (Running on oeis4.)