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!)
A289179 Edge count of the n X n white bishop graph. 1
0, 1, 4, 14, 28, 55, 88, 140, 200, 285, 380, 506, 644, 819, 1008, 1240, 1488, 1785, 2100, 2470, 2860, 3311, 3784, 4324, 4888, 5525, 6188, 6930, 7700, 8555, 9440, 10416, 11424, 12529, 13668, 14910, 16188, 17575, 19000, 20540, 22120, 23821, 25564, 27434, 29348, 31395 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Sequence extended to a(1) using formula.

LINKS

Table of n, a(n) for n=1..46.

Eric Weisstein's World of Mathematics, Edge Count

Eric Weisstein's World of Mathematics, White Bishop Graph

Index entries for linear recurrences with constant coefficients, signature (2, 1, -4, 1, 2, -1).

FORMULA

a(n) = ((-1 + n)*(-3 + 3*(-1)^n - 2*n + 4*n^2))/12.

a(n) = 2*a(n-1)+a(n-2)-4*a(n-3)+a(n-4)+2*a(n-5)-a(n-6).

G.f. = x*(x + 2x^2 + 5x^3)/((-1 + x)^4*(1 + x)^2). [Corrected by Georg Fischer, May 19 2019]

MATHEMATICA

Table[(n - 1) (4 n^2 - 2 n - 3 + 3 (-1)^n)/12, {n, 20}]

LinearRecurrence[{2, 1, -4, 1, 2, -1}, {0, 1, 4, 14, 28, 55}, 20]

CoefficientList[Series[x(x + 2 x^2+ 5 x^3)/((-1 + x)^4 (1 + x)^2), {x, 0, 20}], x] (* Corrected by Georg Fischer, May 19 2019 *)

CROSSREFS

Cf. A225972 (black bishop graph edge count).

Sequence in context: A304342 A066907 A130439 * A033690 A316213 A296985

Adjacent sequences:  A289176 A289177 A289178 * A289180 A289181 A289182

KEYWORD

nonn

AUTHOR

Eric W. Weisstein, Jun 27 2017

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 May 26 01:22 EDT 2020. Contains 334613 sequences. (Running on oeis4.)