login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A144025
Eigentriangle by rows, A001006(n-k)*A005773(k); 0<=k<=n.
0
1, 1, 1, 2, 1, 2, 4, 2, 2, 5, 9, 4, 4, 5, 13, 21, 9, 8, 10, 13, 35, 51, 21, 18, 20, 26, 35, 96, 127, 51, 42, 45, 52, 70, 96, 267, 323, 127, 102, 105, 117, 140, 192, 267, 750, 835, 323, 254, 255, 273, 315, 384, 534, 720, 2123, 2188, 835, 646, 635, 663, 735, 864, 1068
OFFSET
0,4
COMMENTS
Left border = Motzkin numbers, A001006.
Right border = A005773.
Row sums = A005773 shifted: (1, 2, 5, 13, 35, 96, 267,...).
Sum of n-th row terms = rightmost term of next row.
FORMULA
Eigentriangle by rows, A001006(n-k)*A005773(k); 0<=k<=n.
EXAMPLE
First few rows of the triangle =
1;
1, 1;
2, 1, 2;
4, 2, 2, 5;
9, 4, 4, 5, 13;
21, 9, 8, 10, 13, 35;
51, 21, 18, 20, 26, 35, 96;
127, 51, 42, 45, 52, 70, 96, 267;
323, 127, 102, 105, 117, 140, 192, 267, 750;
835, 323, 254, 255, 273, 315, 384, 534, 720, 2123;
...
Row 3 = (4, 2, 2, 5) = termwise product of (4, 2, 1, 1) and the first 4 terms of A005773: (1, 1, 2, 5) = (4*1, 2*1, 1*2, 1*5). (4, 2, 1, 1) = the first 4 terms of A001066, reversed.
CROSSREFS
Sequence in context: A114929 A247321 A152251 * A058573 A184990 A206299
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Sep 07 2008
STATUS
approved