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A228455 Pseudoprimes n to base 2 such that n-2, n+2, n-4 and n+4 are primes. 2
280743771536011785, 666787209284980785, 1386744766793550165, 6558237049521329745, 11646802313400102465 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All numbers in this sequence end in 5 because n-4 , n-2 is a twin prime pair and so also is n+2 and n+4.

For all n, a(n) - 4 is in A230668(n). Somewhat surprisingly, all terms of A230668 known so far are of that form. - M. F. Hasler, Dec 08 2016

LINKS

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

EXAMPLE

280743771536011785 is a pseudoprime (base 2) and 280743771536011781, 280743771536011783, 280743771536011787 and 280743771536011789 are primes.

CROSSREFS

Cf. A001567, A057942, A230488, A230489.

Sequence in context: A337364 A058292 A230668 * A183062 A239923 A104838

Adjacent sequences:  A228452 A228453 A228454 * A228456 A228457 A228458

KEYWORD

nonn,more,hard

AUTHOR

Shyam Sunder Gupta, Oct 27 2013

STATUS

approved

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Last modified May 22 10:55 EDT 2022. Contains 353949 sequences. (Running on oeis4.)