A145099 a(n) = 1 if the largest proper divisor of Mersenne composite A145097(n) is prime and a(n) = 0 in opposite case.

1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0

Offset: 1

Author

Artur Jasinski, Oct 01 2008

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..191

Crossrefs

Cf. A065341, A135975, A135980, A145097, A136031.

Programs

Mathematica

a = {}; Do[m = 2^Prime[n] - 1; k = Divisors[m][[ -2]]; If[PrimeQ[m], null, If[PrimeQ[k], AppendTo[a, 1], AppendTo[a, 0]]], {n, 1, 50}]; a

Extensions

Name clarified and more terms added by Amiram Eldar, Mar 12 2020