A230668 Smallest of 5 consecutive odd numbers that are primes or pseudoprime (base 2).

280743771536011781, 666787209284980781, 1386744766793550161, 6558237049521329741, 11646802313400102461

Offset: 1

Author

Shyam Sunder Gupta, Oct 27 2013

Keywords

• nonn
• hard
• more

Comments

It is conjectured that all numbers in this sequence ends in 1.

All terms known so far are of the form A228455(n) - 4. - M. F. Hasler, Dec 08 2016

Examples

			280743771536011781 is in sequence because 280743771536011781, 280743771536011783, 280743771536011785, 280743771536011787, 280743771536011789 is a set of 5 consecutive odd number where 280743771536011785 is pseudoprime base 2 and others are prime.
		

Crossrefs

Cf. A001567, A228455.

Extensions

Definition reworded by M. F. Hasler, Dec 08 2016