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%I #26 Jun 11 2021 18:25:38
%S 2,3,5,7,11,13,17,23,29,31,37,47,59,61,71,73,97,127,179,181,191,193,
%T 211,239,241,257,359,383,419,421,431,433,479,577,719,769,839,863,1151,
%U 1153,1259,1297,1439,1801,2161,2309,2311,2521,2591,2593,2879,3359,3361
%N Prime numbers p such that p-1 or p+1 is a number of least prime signature (A025487).
%C The corresponding numbers of least prime signature are A344385.
%C 19 is the first prime not in this sequence.
%C This sequence unites many familiar sequences of primes, including Fermat primes (A019434), Mersenne primes (A000668), primorial primes (A018239 and A057705), factorial primes (A088054), A007505, and A039687.
%C Questions: 1) Is this sequence infinite? 2) Is log(a(n)) = O(log(n)^2)?
%H Hal M. Switkay, <a href="/A344384/b344384.txt">Table of n, a(n) for n = 1..158</a>
%e 17 is a term because 17 - 1 = 16 is a number of least prime signature.
%t {2}~Join~Select[Prime@ Range[2, 900], AnyTrue[# + {-1, 1}, Times @@ MapIndexed[Prime[First[#2]]^#1 &, Sort[FactorInteger[#][[All, -1]], Greater] ] == # &] &] (* _Michael De Vlieger_, May 16 2021 *)
%Y Cf. A025487, A344385.
%Y Cf. A000668, A007505, A018239, A019434, A039687, A057705, A088054.
%K nonn
%O 1,1
%A _Hal M. Switkay_, May 16 2021
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