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A227905 Numbers of the form 4k+3 (A004767) that are Lucas pseudoprimes and Fermat pseudoprimes to base 2 (intersection of A005845 and A001567). 1
741751, 1024651, 5481451, 31150351, 109437751, 139952671, 178482151, 284301751, 383425351, 395044651, 407282851, 417027451, 498706651, 582799951, 612816751 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

This sequence uses the Bruckman definition of "Lucas pseudoprime". There are 400,114 examples less than 2^64. - Dana Jacobsen, Jan 07 2015

LINKS

Table of n, a(n) for n=1..15.

J. M. Grau, A. M. Oller-Marcen, M. Rodríguez, D. Sadornil, Fermat test with gaussian base and Gaussian pseudoprimes, arXiv preprint arXiv:1401.4708, 2014

W. Galway, Tables of pseudoprimes and related data [Includes a file with base-2 Fermat pseudoprimes up to 2^64.]

PROG

# Using the Feitsma/Galway database from the links:

(Perl) perl -Mntheory=:all -nE 'chomp; say if ($_%4)==3 && (lucas_sequence($_, 1, -1, $_))[1] == 1' psps-below-2-to-64.txt  # Dana Jacobsen, Jan 07 2015

(Perl) perl -Mntheory=:all -E 'foroddcomposites { say if $_%4 == 3 && ispseudoprime($_, 2) && (lucas_sequence($_, 1, -1, $_))[1] == 1 } 1e14'  # Dana Jacobsen, Jan 10 2015

CROSSREFS

Cf. A004767 (4n+3).

Cf. A001567 (Fermat pseudoprimes to base 2), A005845 (Lucas pseudoprimes).

Sequence in context: A184504 A249317 A251487 * A282407 A147707 A133183

Adjacent sequences:  A227902 A227903 A227904 * A227906 A227907 A227908

KEYWORD

nonn,more

AUTHOR

José María Grau Ribas, Oct 12 2013

EXTENSIONS

More terms from Dana Jacobsen, Jan 07 2015

STATUS

approved

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Last modified November 14 03:44 EST 2017. Contains 294644 sequences.