login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A157433 128n^2 + 2336n + 10657. 3
13121, 15841, 18817, 22049, 25537, 29281, 33281, 37537, 42049, 46817, 51841, 57121, 62657, 68449, 74497, 80801, 87361, 94177, 101249, 108577, 116161, 124001, 132097, 140449, 149057, 157921, 167041, 176417, 186049, 195937, 206081, 216481 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The identity (128*n^2+2336*n+10657)^2-(4*n^2+73*n+333)*( 64*n+584)^2=1 can be written as a(n)^2-A157431(n)* A157432(n)^2=1.

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

Index entries for linear recurrences with constant coefficients, signature (3,-3,1).

FORMULA

a(n) = 3*a(n-1) -3*a(n-2) +a(n-3).

G.f.: x*(-10657*x^2-23522*x-13121)/(x-1)^3

MATHEMATICA

LinearRecurrence[{3, -3, 1}, {13121, 15841, 18817}, 50]

PROG

(MAGMA) I:=[13121, 15841, 18817]; [n le 3 select I[n] else 3*Self(n-1)-3*Self(n-2)+1*Self(n-3): n in [1..50]];

(PARI) a(n)=128*n^2+2336*n+10657 \\ Charles R Greathouse IV, Dec 27 2011

CROSSREFS

Sequence in context: A233689 A250904 A250948 * A089212 A023320 A206149

Adjacent sequences:  A157430 A157431 A157432 * A157434 A157435 A157436

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Mar 01 2009

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 July 11 21:30 EDT 2020. Contains 335652 sequences. (Running on oeis4.)