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A135151
A002260 + A128174 - I, I = Identity matrix.
2
1, 1, 2, 2, 2, 3, 1, 3, 3, 4, 2, 2, 4, 4, 5, 1, 3, 3, 5, 5, 6, 2, 2, 4, 4, 6, 6, 7, 1, 3, 3, 5, 5, 7, 7, 8, 2, 2, 4, 4, 6, 6, 8, 8, 9, 1, 3, 3, 5, 5, 7, 7, 9, 9, 10
OFFSET
1,3
COMMENTS
A135152 is a companion triangle, both having row sums = A047838: (1, 3, 7, 11, 17, 23, 31, 39, ...).
FORMULA
A002260 + A128174 - I, where I = Identity matrix, A002260 = (1; 1,2; 1,2,3; ...) and A128174 = (1; 0,1; 1,0,1; 0,1,0,1; ...).
EXAMPLE
First few rows of the triangle:
1;
1, 2;
2, 2, 3;
1, 3, 3, 4;
2, 2, 4, 4, 5;
1, 3, 3, 5, 5, 6;
2, 2, 4, 4, 6, 6, 7;
...
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Gary W. Adamson, Nov 21 2007
STATUS
approved