|
Search: id:A108959
|
|
|
| A108959 |
|
Triangle arising in connection with deformations of type D Kleinian singularities. |
|
+0
1
|
|
| 1, 2, 1, 3, 4, 2, 4, 10, 14, 7, 5, 20, 54, 76, 38, 6, 35, 154, 419, 590, 295, 7, 56, 364, 1616, 4400, 6196, 3098, 8, 84, 756, 4962, 22048, 60036, 84542, 42271, 9, 120
(list; table; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
REFERENCES
|
P. Boddington, Ph.D. thesis, University of Warwick, 2005.
|
|
FORMULA
|
For k>=0 define p_k(x)=x(x+1)(x+3)...(x+k(k-1)/2) and consider the linear map taking each p_k(x) to kp_k(x)/x. Then the images of x, x^2, x^3, ... are given by the rows. Eg x^3 goes to 3x^2+4x+2.
|
|
CROSSREFS
|
This sequence is an improved version of A097418. Coefficients of 1 give A000366.
Sequence in context: A120058 A102756 A086614 this_sequence A107893 A131987 A120874
Adjacent sequences: A108956 A108957 A108958 this_sequence A108960 A108961 A108962
|
|
KEYWORD
|
easy,nonn,tabl
|
|
AUTHOR
|
Paul Boddington (psb(AT)maths.warwick.ac.uk), Jul 22 2005
|
|
|
Search completed in 0.002 seconds
|
