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!)
A145923 Second bisection of A061041: a(n) = A061041(2n+1) = (2n+1)*(2n+9). 4
9, 33, 65, 105, 153, 209, 273, 345, 425, 513, 609, 713, 825, 945, 1073, 1209, 1353, 1505, 1665, 1833, 2009, 2193, 2385, 2585, 2793, 3009, 3233, 3465, 3705, 3953, 4209, 4473, 4745, 5025, 5313, 5609, 5913, 6225, 6545, 6873, 7209, 7553, 7905, 8265, 8633, 9009, 9393 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..46.

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

FORMULA

a(n) = 9 + 4*n^2 + 20*n. - Paolo P. Lava, Oct 28 2008

G.f.: (-9-6*x+7*x^2)/(x-1)^3 . - R. J. Mathar, Oct 23 2016

PROG

(PARI) a(n)=4*n^2+20*n+9 \\ Charles R Greathouse IV, Jun 17 2017

CROSSREFS

Sequence in context: A175369 A046895 A165392 * A092562 A103602 A205796

Adjacent sequences:  A145920 A145921 A145922 * A145924 A145925 A145926

KEYWORD

nonn,easy,less

AUTHOR

Paul Curtz, Oct 25 2008

EXTENSIONS

More terms from Jinyuan Wang, Mar 23 2020

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 August 8 19:29 EDT 2020. Contains 336298 sequences. (Running on oeis4.)