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

280743771536011781, 666787209284980781, 1386744766793550161, 6558237049521329741, 11646802313400102461

Offset

1,1

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

Links

Table of n, a(n) for n=1..5.

Example

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.

Sequence in context: A337364 A058292 A363980 * A228455 A183062 A239923

Adjacent sequences: A230665 A230666 A230667 * A230669 A230670 A230671

Keyword

nonn,hard,more

Author

Shyam Sunder Gupta, Oct 27 2013

Extensions

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

Status

approved