login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A231200 Boustrophedon transform of even numbers. 4
0, 2, 8, 24, 72, 240, 924, 4116, 20944, 119952, 763540, 5346748, 40845816, 338041704, 3012855356, 28770647220, 293055401888, 3171602665696, 36343889387172, 439607533130732, 5597256953340360, 74829813397495128, 1048039052970587788, 15345654816688856484 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..400

Peter Luschny, An old operation on sequences: the Seidel transform

J. Millar, N. J. A. Sloane and N. E. Young, A new operation on sequences: the Boustrophedon transform, J. Combin. Theory, 17A 44-54 1996 (Abstract, pdf, ps).

Wikipedia, Boustrophedon_transform

Index entries for sequences related to boustrophedon transform

FORMULA

a(n) = Sum_{k=0..n} A109449(n,k)*k*2.

a(n) = 2*A231179(n).

E.g.f.: 2*x*exp(x)*(sec(x) + tan(x)). - Ilya Gutkovskiy, Sep 27 2017

MATHEMATICA

T[n_, k_] := SeriesCoefficient[(1+Sin[x])/Cos[x], {x, 0, n-k}] n!/k!;

a[n_] := 2 Sum[k T[n, k], {k, 0, n}];

Table[a[n], {n, 0, 23}] (* Jean-Fran├žois Alcover, Jun 28 2019 *)

PROG

(Haskell)

a231200 n = sum $ zipWith (*) (a109449_row n) $ [0, 2 ..]

CROSSREFS

Cf. A005843, A000754.

Sequence in context: A045697 A131569 A290904 * A066973 A130495 A026070

Adjacent sequences:  A231197 A231198 A231199 * A231201 A231202 A231203

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Nov 05 2013

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 20 15:07 EDT 2019. Contains 326152 sequences. (Running on oeis4.)