The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A047991 Triangle formed from expansion of (x-1)(x+2)(x-3)...(x+-n). 4
 1, 1, -1, 1, 1, -2, 1, -2, -5, 6, 1, 2, -13, -14, 24, 1, -3, -23, 51, 94, -120, 1, 3, -41, -87, 400, 444, -720, 1, -4, -62, 200, 1009, -2356, -3828, 5040, 1, 4, -94, -296, 2609, 5716, -22676, -25584, 40320, 1, -5, -130, 550, 5273, -17765, -74120, 178500, 270576, -362880 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 REFERENCES Studied by M. Bhargava (bhargava(AT)math.Princeton.EDU) and H. S. Wilf. LINKS T. D. Noe, Rows n=0..100 of triangle, flattened EXAMPLE Triangle begins 1; 1, -1; 1, 1, -2; 1, -2, -5, 6; 1, 2, -13, -14, 24; 1, -3, -23, 51, 94, -120; 1, 3, -41, -87, 400, 444, -720; 1, -4, -62, 200, 1009, -2356, -3828, 5040; 1, 4, -94, -296, 2609, 5716, -22676, -25584, 40320; MATHEMATICA With[{nn=10}, Flatten[Table[Reverse[CoefficientList[Series[Times@@ Table[x+n (-1)^n, {n, i}], {x, 0, nn}], x]], {i, 0, nn}]]] (* Harvey P. Dale, Aug 28 2012 *) CROSSREFS A047990 gives sums of absolute values of rows. Sequence in context: A098509 A019910 A084309 * A296666 A120898 A153910 Adjacent sequences: A047988 A047989 A047990 * A047992 A047993 A047994 KEYWORD sign,tabl,easy,nice AUTHOR N. J. A. Sloane STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified August 15 05:59 EDT 2024. Contains 375172 sequences. (Running on oeis4.)