login
A104792
Triangle T(n,k) = A000330(n-k), n>=1, 0<=k<n, read by rows.
0
1, 5, 1, 14, 5, 1, 30, 14, 5, 1, 55, 30, 14, 5, 1, 91, 55, 30, 14, 5, 1, 140, 91, 55, 30, 14, 5, 1, 204, 140, 91, 55, 30, 14, 5, 1, 285, 204, 140, 91, 55, 30, 14, 5, 1, 385, 285, 204, 140, 91, 55, 30, 14, 5, 1, 506, 385, 285, 204, 140, 91, 55, 30, 14, 5, 1, 650, 506, 385, 285
OFFSET
1,2
COMMENTS
Repeatedly writing the square pyramidal numbers (A000330) backwards.
FORMULA
T(n,k) = (n-k)(n-k+1)(2n-2k+1)/6 = A000330(A004736(n)). - Ralf Stephan, Apr 05 2009
EXAMPLE
First few rows of the triangle are:
1;
5, 1;
14, 5, 1;
30, 14, 5, 1;
55, 30, 14, 5, 1;
91, 55, 30, 14, 5, 1;
...
CROSSREFS
Row sums are in A002415. Antidiagonals are in A000332.
Sequence in context: A174504 A270654 A067558 * A120393 A370518 A094368
KEYWORD
nonn,easy,tabl
AUTHOR
Gary W. Adamson, Mar 26 2005
EXTENSIONS
Edited by Ralf Stephan, Apr 05 2009
STATUS
approved