A337626 - OEIS

A337626

Odd composite integers m such that U(m)^2 == 1 (mod m) and V(m) == 3 (mod m), where U(m) and V(m) are the m-th generalized Lucas and Pell-Lucas numbers of parameters a=3 and b=-1, respectively.

33, 119, 385, 561, 649, 1189, 1441, 2065, 2289, 2465, 2849, 4187, 6545, 12871, 13281, 14041, 16109, 18241, 22049, 23479, 24769, 25345, 28421, 31631, 34997, 38121, 38503, 41441, 45961, 48577, 50545, 53585, 56279, 58081, 59081, 61447, 63393, 66385, 75077, 91187

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OFFSET

1,1

COMMENTS

Intersection of A335669 and A337234.

For a,b integers, the following sequences are defined:

generalized Lucas sequences by U(n+2)=a*U(n+1)-b*U(n) and U(0)=0, U(1)=1,

generalized Pell-Lucas sequences by V(n+2)=a*V(n+1)-b*V(n) and V(0)=2, V(1)=a.

These satisfy the identities U(p)^2 == 1 and V(p)==a (mod p) for p prime and b=1,-1.

These numbers may be called weak generalized Lucas-Bruckner pseudoprimes of parameters a and b.The current sequence is defined for a=3 and b=-1.

LINKS

Table of n, a(n) for n=1..40.