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A157423
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Triangle read by rows, T(n,k) = 0 if (n-k+1) is prime, else 1.
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2
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1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Row sums = A062298: (1, 1, 1, 2, 2, 3, 3, 4, 5, 6,...). Eigensequence of the triangle = A052284: (1, 1, 1, 2, 3, 5, 7, 11, 17, 27,...).
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FORMULA
| Triangle read by rows, T(n,k) = 0 if (n-k+1) is prime, else 1. By columns, A005171 in every column: where A005171(k) = 0 if k is prime.
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EXAMPLE
| First few rows of the triangle =
1;
0, 1;
0, 0, 1;
1, 0, 0, 1;
0, 1, 0, 0, 1;
1, 0, 1, 0, 0, 1;
0, 1, 0, 1, 0, 0, 1;
1, 0, 1, 0, 1, 0, 0, 1;
1, 1, 0, 1, 0, 1, 0, 0, 1;
1, 1, 1, 0, 1, 0, 1, 0, 0, 1;
0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1;
1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1;
0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1;
1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1;
...
Example: T(6,4) = 0 since (6 - 4 + 1) = 3, prime.
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CROSSREFS
| Cf. A005171, A062298, A052284, A157424
Sequence in context: A152490 A145273 A120522 * A098033 A135022 A071982
Adjacent sequences: A157420 A157421 A157422 * A157424 A157425 A157426
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KEYWORD
| nonn,tabl
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AUTHOR
| Gary W. Adamson & Mats Granvik (qntmpkt(AT)yahoo.com), Feb 28 2009
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