A128193 First differences of values of n for Cullen primes in A005849.

140, 4572, 1082, 816, 11885, 13796, 177, 27187, 31169, 171594, 98856, 120624, 872929, 4973720, 351333

Offset: 1

Author

Enoch Haga, Feb 18 2007

Keywords

• nonn
• more

Comments

Carlos Rivera's Problem 50 is devoted to this topic. If we pair differences according to magnitude, we first obtain 177-140=37 a prime. This raises the question as to whether there are other such prime values.

Examples

			a(1)=140 because the first pair of n are 1 and 141. 141 - 1 = 140.
		

Links

• Carlos Rivera, Problem 50. Is there a Cullen prime Cn with n prime?, The Prime Puzzles and Problems Connection.

Crossrefs

Cf. A005849, A128194.

Formula

a(n) = A005849(n+1) - A005849(n). - Michel Marcus, Sep 27 2020

Extensions

Offset 1 from Michel Marcus, Sep 27 2020

a(14)-a(15) added by Florian Baur, Sep 27 2020