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A144217
Weight array of A144216: a rectangular array by antidiagonals.
2
0, 1, 1, 2, 0, 2, 3, 0, 0, 3, 4, 0, 0, 0, 4, 5, 0, 0, 0, 0, 5, 6, 0, 0, 0, 0, 0, 6, 7, 0, 0, 0, 0, 0, 0, 7, 8, 0, 0, 0, 0, 0, 0, 0, 8, 9, 0, 0, 0, 0, 0, 0, 0, 0, 9, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 10, 11, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 12, 13, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
OFFSET
1,4
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..11325 (antidiagonals 1..150 of the array, flattened).
FORMULA
Start with R(m,n)=(m(m-1)+n(n-1))/2 for m>=1,n>=1. Put R(m,n)=0 if m=0 or n=0. Define w(m,n)=R(m,n)-R(m-1,n-1)-R(m,n-1)-R(m-1,n) for m>=1, n>=1. Then the weight array W={w(m,n)} is A144217. (See A144112.)
EXAMPLE
Northwest corner:
0 1 2 3 4 5
1 0 0 0 0 0
2 0 0 0 0 0
3 0 0 0 0 0
4 0 0 0 0 0
MATHEMATICA
Array[Append[PadRight[{#}, #, 0], #]&, 15, 0] (* Paolo Xausa, Dec 21 2023 *)
CROSSREFS
Cf. A144217.
Sequence in context: A293578 A098489 A128064 * A187881 A344839 A344836
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Sep 14 2008
STATUS
approved