1,2

a(n) = a(A007947(n)); n is prime iff a(n)=n.

Paul Tek, Table of n, a(n) for n = 1..10000

a(35) = a(5*7) = a(5) 'or' a(7) = '101' or '111' = '111' = 7.

(Haskell)

import Data.Bits (((.|.))

a072593 = foldl1 (.|.) . a027746_row -- Reinhard Zumkeller, Jul 05 2013

Cf. A072591, A072594.

Cf. A027746.

Sequence in context: A145254 A163457 A285708 * A039635 A164858 A192330

Adjacent sequences: A072590 A072591 A072592 * A072594 A072595 A072596

nonn

Reinhard Zumkeller, Jun 23 2002

approved