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!)
A018839 Squares on infinite chessboard at n moves from center using a {2,3} fairy knight. 3
1, 8, 32, 88, 192, 304, 372, 416, 472, 540, 608, 676, 744, 812, 880, 948, 1016, 1084, 1152, 1220, 1288, 1356, 1424, 1492, 1560, 1628, 1696, 1764, 1832, 1900, 1968, 2036, 2104, 2172, 2240, 2308, 2376, 2444, 2512, 2580, 2648, 2716, 2784, 2852, 2920, 2988 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (2,-1).

FORMULA

For n >= 8, a(n) = 68n - 72. - David W. Wilson

G.f.: (x+1)*(12*x^8 - 24*x^6 - 20*x^5 + 28*x^4 + 20*x^3 + 12*x^2 + 5*x + 1)/(x-1)^2. - Colin Barker, Oct 04 2012

MATHEMATICA

CoefficientList[Series[(x + 1) (12 x^8 - 24 x^6 - 20 x^5 + 28 x^4 + 20 x^3 + 12 x^2 + 5*x + 1)/(x - 1)^2, {x, 0, 50}], x] (* Vincenzo Librandi, Oct 16 2013 *)

CROSSREFS

Cf. A297740 (partial sums).

Sequence in context: A211633 A130809 A333174 * A008412 A014819 A033155

Adjacent sequences:  A018836 A018837 A018838 * A018840 A018841 A018842

KEYWORD

nonn,easy

AUTHOR

Marc LeBrun

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 2 09:22 EDT 2021. Contains 346422 sequences. (Running on oeis4.)