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A060229
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Smaller member of a twin prime pair whose mean is a multiple of A002110(3)=30.
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18
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29, 59, 149, 179, 239, 269, 419, 569, 599, 659, 809, 1019, 1049, 1229, 1289, 1319, 1619, 1949, 2129, 2309, 2339, 2549, 2729, 2789, 2969, 2999, 3119, 3299, 3329, 3359, 3389, 3539, 3929, 4019, 4049, 4229, 4259, 4649, 4799, 5009, 5099, 5279, 5519, 5639
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OFFSET
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1,1
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COMMENTS
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Equivalently, smaller of twin prime pair with primes in different decades.
Primes p such that p and p+2 are prime factors of Fibonacci(p-1) and Fibonacci(p+1) respectively. - Michel Lagneau, Jul 13 2016
Number of terms less than 10^k, k=2,3,4,...: 2, 11, 72, 407, 2697, 19507, 146516, ... - Muniru A Asiru, Jan 29 2018
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LINKS
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EXAMPLE
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For the pair {149,151} (149 + 151)/2 = 5*30.
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MAPLE
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isA060229 := proc(n)
if modp(n+1, 30) =0 and isprime(n) and isprime(n+2) then
true;
else
false;
end if;
end proc:
option remember;
if n =1 then
29;
else
for a from procname(n-1)+2 by 2 do
if isA060229(a) then
return a;
end if;
end do:
end if;
end proc:
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MATHEMATICA
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Select[Prime@ Range[10^3], PrimeQ[# + 2] && Mod[# + 1, 30] == 0 &] (* Michael De Vlieger, Jul 14 2016 *)
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PROG
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(PARI) isok(n) = isprime(n) && isprime(n+2) && !((n+1) % 30); \\ Michel Marcus, Dec 11 2013
(Magma) [p: p in PrimesUpTo(7000) | IsPrime(p+2) and p mod 30 eq 29 ]; // Vincenzo Librandi, Feb 13 2017
(GAP) Filtered(List([0..200], k -> 30*k-1), n -> IsPrime(n) and IsPrime(n+2)); # Muniru A Asiru, Feb 02 2018
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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