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A087380
Let Pricom(n) be defined as the number obtained by replacing each prime digit (2,3,5,7) of n with a '0' and a composite digit (0,4,6,8,9) with a '1' . A 1 remains the same. a(n) = Pricom(n).
1
1, 0, 0, 1, 0, 1, 0, 1, 1, 11, 11, 10, 10, 11, 10, 11, 10, 11, 11, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 11, 11, 10, 10, 11, 10, 11, 10, 11, 11, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 11, 11, 10, 10, 11, 10, 11, 10, 11, 11, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 11, 11, 10, 10, 11, 10, 11, 10
OFFSET
1,10
COMMENTS
For all numbers using only prime digits a(n) = 0. For a 'k' digit number using 1 and/or only composite digits a(n) = (10^k-1)/9.
EXAMPLE
a(4206) = 1011
a(10235479) = 11000101.
CROSSREFS
Cf. A087381.
Sequence in context: A300289 A321108 A126610 * A152986 A252838 A366717
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Sep 09 2003
EXTENSIONS
More terms from David Wasserman, May 25 2005
STATUS
approved