This site is supported by donations to The OEIS Foundation.

 Annual Appeal: Please make a donation to keep the OEIS running. In 2018 we replaced the server with a faster one, added 20000 new sequences, and reached 7000 citations (often saying "discovered thanks to the OEIS"). Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A117435 Triangle related to exp(x)cos(2x). 2

%I

%S 1,0,1,-4,0,1,0,-12,0,1,16,0,-24,0,1,0,80,0,-40,0,1,-64,0,240,0,-60,0,

%T 1,0,-448,0,560,0,-84,0,1,256,0,-1792,0,1120,0,-112,0,1,0,2304,0,

%U -5376,0,2016,0,-144,0,1,-1024,0,11520,0,-13440,0,3360,0,-180,0,1

%N Triangle related to exp(x)cos(2x).

%C Row sums are A006495 (with e.g.f. exp(x)cos(2x)). Inverse is A117436. Diagonal sums are (1,0,-3,0,5,0,-7,...). Diagonals correspond to rows of A117438.

%F Number triangle whose k-th column has e.g.f. (x^k/k!)*cos(2x); T(n,k)=C(n,k)*(-4)^((n-k)/2)*(1+(-1)^(n-k))/2.

%e Triangle begins

%e 1,

%e 0, 1,

%e -4, 0, 1,

%e 0, -12, 0, 1,

%e 16, 0, -24, 0, 1,

%e 0, 80, 0, -40, 0, 1,

%e -64, 0, 240, 0, -60, 0, 1

%Y Cf. A117411.

%K easy,sign,tabl

%O 0,4

%A _Paul Barry_, Mar 16 2006

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.

Last modified December 13 20:06 EST 2018. Contains 318087 sequences. (Running on oeis4.)