This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A110509 Riordan array (1, x(1-2x)). 6
 1, 0, 1, 0, -2, 1, 0, 0, -4, 1, 0, 0, 4, -6, 1, 0, 0, 0, 12, -8, 1, 0, 0, 0, -8, 24, -10, 1, 0, 0, 0, 0, -32, 40, -12, 1, 0, 0, 0, 0, 16, -80, 60, -14, 1, 0, 0, 0, 0, 0, 80, -160, 84, -16, 1, 0, 0, 0, 0, 0, -32, 240, -280, 112, -18, 1, 0, 0, 0, 0, 0, 0, -192, 560, -448, 144, -20, 1, 0, 0, 0, 0, 0, 0, 64, -672, 1120, -672, 180, -22, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Inverse is Riordan array (1,xc(2x)) [A110510]. Row sums are A107920(n+1). Diagonal sums are (-1)^n*A052947(n). LINKS G. C. Greubel, Table of n, a(n) for the first 50 rows, flattened FORMULA Number triangle: T(n, k) = (-2)^(n-k)*binomial(k, n-k). T(n,k) = A109466(n,k)*2^(n-k). - Philippe Deléham, Oct 26 2008 EXAMPLE Rows begin 1; 0,  1; 0, -2,  1; 0,  0, -4,  1; 0,  0,  4, -6,  1; 0,  0,  0, 12, -8,   1; 0,  0,  0, -8, 24, -10, 1; MATHEMATICA T[n_, k_] := (-2)^(n - k)*Binomial[k, n - k]; Table[T[n, k], {n, 0, 49}, {k, 0, n}] // Flatten (* G. C. Greubel, Aug 29 2017 *) PROG (PARI) for(n=0, 25, for(k=0, n, print1((-2)^(n-k)*binomial(k, n-k), ", "))) \\ G. C. Greubel, Aug 29 2017 CROSSREFS Sequence in context: A065719 A204387 A113953 * A319574 A204040 A220779 Adjacent sequences:  A110506 A110507 A110508 * A110510 A110511 A110512 KEYWORD easy,sign,tabl AUTHOR Paul Barry, Jul 24 2005 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 23 18:46 EDT 2018. Contains 316530 sequences. (Running on oeis4.)