A239548 Primes p such that gcd(Lucas(p), Mersenne(p)) > 1.
2, 179, 239, 359, 419, 487, 659, 719, 883, 1013, 1019, 1439, 1459, 1499, 1559, 1723, 1871, 1993, 2039, 2339, 2399, 2459, 2593, 2699, 2819, 2939, 3041, 3299, 3329, 3359, 3539, 3779, 4019, 4813, 4919, 4957, 5039, 5231, 5261, 5279, 5399, 5639, 6011, 6353, 6373
Offset: 1
Keywords
Examples
239 is in the sequence since it is prime and 479 is a prime factor of both Lucas(239) and Mersenne(239) = 2^239 - 1.
Links
- Eric Weisstein's World of Mathematics, Lucas Number
- Eric Weisstein's World of Mathematics, Mersenne Number
Programs
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Magma
[p: p in PrimesUpTo(6500) | Gcd(Lucas(p),2^p-1) gt 1];
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PARI
for(p=2, 6373, if(isprime(p)&&gcd(fibonacci(p-1)+fibonacci(p+1), 2^p-1)>1, print1(p, ", ")));