A230668 - OEIS

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A230668

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

280743771536011781, 666787209284980781, 1386744766793550161, 6558237049521329741, 11646802313400102461

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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