A103964 Record values in A040076.

0, 1, 2, 3, 6, 8, 583, 6393, 9715, 33288, 3321063, 5054502, 31172165

Offset: 1

Author

Lei Zhou, Feb 24 2005

Keywords

• nonn
• more

Comments

The index sequence of this sequence is 1, 3, 7, 17, 19, 31, 47, 383, 2897. A040076(2897)>8192, not yet found.

A064699 gives where the records occur.

Examples

			A040076(1)=0, so a(1)=0;
A040076(3)=1, so a(2)=1;
		

Crossrefs

Cf. A040076, A103963.

Programs

Mathematica

k = -1; n = 0; km = k; While[k < 8192, n++; k = 0; cp = n*(2^ k) + 1; While[(! PrimeQ[cp]) && (k < 8192), k++; cp = n*(2^k) + 1]; If[k > km, km = k; Print[{n, km}]]]

Extensions

Extended by T. D. Noe, Nov 15 2010

a(13) was found by PrimeGrid, added by Richard N. Smith, Jul 15 2019