|
|
A110425
|
|
The r-th term of the n-th row of the following array contains the sum of r successively decreasing integers beginning from n. 0<r<=n. e.g. the row corresponding to 4 contains 4, (3+2),{(1) +(0)+(-1)}, {(-2)+(-3)+(-4)+(-5)} ----> 4,5,0,-14 1 2 1 3 3 -3 4 5 0 -14 5 7 3 -10 -35 6 9 6 -6 -30 -69 ... Sequence contains the array by rows.
|
|
3
|
|
|
1, 2, 1, 3, 3, -3, 4, 5, 0, -14, 5, 7, 3, -10, -35, 6, 9, 6, -6, -30, -69, 7, 11, 9, -2, -25, -63, -119, 8, 13, 12, 2, -20, -57, -112, -188, 9, 15, 15, 6, -15, -51, -105, -180, -279, 10, 17, 18, 10, -10, -45, -98, -172, -270, -395, 11, 19, 21, 14, -5, -39, -91, -164, -261, -385, -539, 12, 21, 24, 18, 0, -33, -84, -156, -252
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
LINKS
|
Table of n, a(n) for n=1..75.
|
|
EXAMPLE
|
The r-th term of the n-th row of the following array contains the sum of r successively decreasing integers beginning from n. 0<r<=n.
e.g. the row corresponding to 4 contains
4, (3+2),{(1) +(0)+(-1)}, {(-2)+(-3)+(-4)+(-5)} ----> 4,5,0,-14
1
2 1
3 3 -3
4 5 0 -14
5 7 3 -10 -35
Sequence contains the array by rows.
|
|
PROG
|
;; PLT DrScheme (Zucker)
(define (triangle n) (* n (add1 n) 1/2))
(define (A110425 n)
(build-list n (lambda (r) (- (triangle (- n (triangle r)))
(triangle (- n (triangle (add1 r))))))))
|
|
CROSSREFS
|
Cf. A110426, A110427.
Sequence in context: A085599 A299966 A302395 * A174257 A105637 A029161
Adjacent sequences: A110422 A110423 A110424 * A110426 A110427 A110428
|
|
KEYWORD
|
easy,sign,tabl
|
|
AUTHOR
|
Amarnath Murthy, Aug 01 2005
|
|
EXTENSIONS
|
More terms from Joshua Zucker, May 10 2006
|
|
STATUS
|
approved
|
|
|
|