A077806 Greatest prime factor of numbers containing in their decimal representation only the digits 0 and 1.

1, 5, 11, 5, 101, 11, 37, 5, 13, 101, 337, 11, 367, 37, 101, 5, 137, 13, 71, 101, 37, 337, 10111, 11, 193, 367, 13, 37, 653, 101, 271, 5, 9091, 137, 53, 13, 547, 71, 479, 101, 257, 37, 1217, 337, 101, 10111, 101111, 11, 991, 193, 137, 367, 4787, 13, 739, 37

Offset

1,2

Links

Table of n, a(n) for n=1..56.

Formula

a(n) = A006530(A007088(n)).

Example

a(45) = A006530(A007088(45)) = A006530(101101) = A006530(7*11*13*101) = 101.

Mathematica

FactorInteger[#][[-1, 1]]&/@Rest[FromDigits/@Tuples[{0, 1}, 6]] (* Harvey P. Dale, Feb 07 2015 *)

Crossrefs

Cf. A077805, A020449.

Sequence in context: A110353 A377050 A097720 * A365731 A019305 A274266

Adjacent sequences: A077803 A077804 A077805 * A077807 A077808 A077809

Keyword

nonn,base

Author

Reinhard Zumkeller, Nov 16 2002

Status

approved