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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
15, 21, 51, 99, 249, 309, 339, 441, 615, 1065, 1071, 1275, 1311, 1461, 1665, 1719, 1935, 2445, 2451, 2499, 2511, 2781, 2829, 2949, 3015, 3129, 3435, 3759, 3789, 3795, 3819, 3939, 4161, 4221, 4761, 4809, 5709, 5721, 6291, 6555, 6699, 6855, 6921, 7071
OFFSET
1,1
EXAMPLE
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.
CROSSREFS
KEYWORD
nonn
AUTHOR
Neil Fernandez, Jul 09 2001
EXTENSIONS
Edited and extended by Robert G. Wilson v, Feb 07 2002
STATUS
approved