A087381 Let Compri(n) be the number obtained by replacing each prime digit (2,3,5,7) of n with a '1' and a composite digit( 0,4,6,8,9) with a '0'. A 1 remains the same. a(n) = Compri(n).

1, 1, 1, 0, 1, 0, 1, 0, 0, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 10, 11, 11, 11, 10, 11, 10, 11, 10, 10, 0

Offset

1,10

Comments

For all numbers using only composite digits (0,4,6,8,9) a(n) = 0. For a 'k' digit number using 1 and/or only prime digits a(n) = (10^k-1)/9.

Links

Table of n, a(n) for n=1..80.

Example

a(4206) = 100
a(10235479) = 10111010

Mathematica

Join[{1}, Table[FromDigits[IntegerDigits[n]/.{2->1, 3->1, 4->0, 5->1, 6->0, 7->1, 8->0, 9->0}], {n, 2, 100}]] (* Harvey P. Dale, Jul 12 2020 *)

Crossrefs

Cf. A087380.

Sequence in context: A077812 A004288 A065016 * A136400 A334027 A121266

Adjacent sequences: A087378 A087379 A087380 * A087382 A087383 A087384

Keyword

base,nonn

Author

Amarnath Murthy, Sep 09 2003

Extensions

More terms from David Wasserman, May 25 2005

Status

approved