

A018844


Arises from generalized LucasLehmer test for primality.


2



4, 10, 52, 724, 970, 10084, 95050, 140452, 1956244, 9313930, 27246964, 379501252, 912670090, 5285770564, 73621286644, 89432354890, 1025412242452, 8763458109130, 14282150107684, 198924689265124
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OFFSET

1,1


COMMENTS

Apparently this was suggested by an article by R. M. Robinson.
Starting values for LucasLehmer test that result in a zero term (mod Mersenne prime Mp) after P1 steps.  Jason Follas (jfollas_mersenne(AT)hotmail.com), Aug 01 2004
m belongs to the sequence iff m2 is twice a square and m+2 is either three or six times a square.  RenĂ© Gy, Jan 10 2019


LINKS

Table of n, a(n) for n=1..20.
Herb Savage et al., Re: Mersenne: starting values for LLtest


FORMULA

Union of sequences a_1=4, a_2=52, a_{n}=14*a_{n1}  a_{n2} and b_1=10, b_2=970, b_{n}=98*b_{n1}  b_{n2}.
a[1]=14 (mod Mp), a[2]=52 (mod Mp), a[n]=(14*a[n1]a[n2]) (mod Mp).  Jason Follas (jfollas_mersenne(AT)hotmail.com), Aug 01 2004
Though originally noted as the union of two sequences, when the first sequence (14*a[n1]a[n2]) is evaluated modulo a Mersenne prime, the terms of the second sequence (98*b[n1]b[n2]) will occur naturally (just not in numerical order).  Jason Follas (jfollas_mersenne(AT)hotmail.com), Aug 01 2004
a(n) = sqrt(A206257(n) + 2). [Arkadiusz Wesolowski, Feb 08 2012]


CROSSREFS

Sequence in context: A208236 A032495 A109387 * A007027 A192444 A197902
Adjacent sequences: A018841 A018842 A018843 * A018845 A018846 A018847


KEYWORD

easy,nonn


AUTHOR

Robert G. Wilson v


STATUS

approved



