This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A230960 Boustrophedon transform of factorials, cf. A000142. 4
 1, 2, 5, 17, 73, 381, 2347, 16701, 134993, 1222873, 12279251, 135425553, 1627809401, 21183890469, 296773827547, 4453511170517, 71275570240417, 1211894559430065, 21816506949416611, 414542720924028441, 8291224789668806345, 174120672081098057341 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS a(n) = sum(A109449(n,k)*A000142(k), k=0..n). 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 FORMULA a(n) = sum(A109449(n,k)*A000142(k), k=0..n). E.g.f.: (tan(x)+sec(x))/(1-x) = (1- 12*x/(Q(0)+6*x+3*x^2))/(1-x), where Q(k) = 2*(4*k+1)*(32*k^2+16*k-x^2-6) - x^4*(4*k-1)*(4*k+7)/Q(k+1) ; (continued fraction). - Sergei N. Gladkovskii, Nov 18 2013 a(n) ~ n! * (1+sin(1))/cos(1). - Vaclav Kotesovec, Jun 12 2015 PROG (Haskell) a230960 n = sum \$ zipWith (*) (a109449_row n) a000142_list CROSSREFS Cf. A230961. Sequence in context: A108289 A007779 A084161 * A102038 A002135 A260337 Adjacent sequences:  A230957 A230958 A230959 * A230961 A230962 A230963 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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 17 14:25 EDT 2018. Contains 316281 sequences. (Running on oeis4.)