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A132918
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Identity matrix with interpolated zeros.
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1
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1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Given A132918 = matrix M, then M * any sequence as a vector replaces alternate terms with zeros; e.g. M * [1,2,3,...] = [1,0,3,0,5,...]. M * (any infinite lower triangular matrix) replaces alternate rows with zeros; e.g. M * A007318 = (1; 0,0; 1,2,1; 0,0,0,0;...).
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FORMULA
| Identity matrix with interpolated zeros, such that the diagonal of an infinite lower triangular matrix = (1, 0, 1, 0, 1,...) with the rest zeros. a(n) = 1 if n = a hexagonal number, A000384: (1, 6, 15, 28, 45, 66,...); zero otherwise.
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EXAMPLE
| First few rows of the triangle are:
1;
0, 0;
0, 0, 1;
0, 0, 0, 0;
0, 0, 0, 0, 1;
...
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CROSSREFS
| Sequence in context: A015959 A014834 A015659 * A133943 A014084 A014159
Adjacent sequences: A132915 A132916 A132917 * A132919 A132920 A132921
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KEYWORD
| nonn,tabl
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AUTHOR
| Gary W. Adamson (qntmpkt(AT)yahoo.com), Sep 05 2007
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