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A063176 Composites for which the row of the prime-composite array (A063173) includes the leftmost element of both a zero-only antidiagonal and a zero-only diagonal(A067681). 4

%I

%S 15,21,51,99,249,309,339,441,615,1065,1071,1275,1311,1461,1665,1719,

%T 1935,2445,2451,2499,2511,2781,2829,2949,3015,3129,3435,3759,3789,

%U 3795,3819,3939,4161,4221,4761,4809,5709,5721,6291,6555,6699,6855,6921,7071

%N Composites for which the row of the prime-composite array (A063173) includes the leftmost element of both a zero-only antidiagonal and a zero-only diagonal(A067681).

%H N. Fernandez, <a href="http://www.borve.org/primeness/pcarray.html">The prime-composite array, B(m,n) and the Borve conjectures</a>

%e The 12th composite is 21. In the prime-composite array (A063173), all of the elements in the antidiagonal containing T(12,1) are 0 and so are all the elements of the diagonal containing T(12,1). So 21 is in the sequence.

%Y Cf. A063173, A063174, A063175, A067681.

%K nonn

%O 1,1

%A _Neil Fernandez_, Jul 09 2001

%E Edited and extended by _Robert G. Wilson v_, Feb 07 2002

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Last modified April 4 23:59 EDT 2020. Contains 333238 sequences. (Running on oeis4.)