login
A172070
Primes p such that either p-1/2-+5/2, but not both, is prime.
0
3, 11, 17, 29, 41, 59, 71, 101, 107, 137, 149, 179, 191, 197, 227, 239, 269, 281, 311, 347, 419, 431, 461, 521, 569, 599, 617, 641, 659, 809, 821, 827, 857, 881, 1019, 1031, 1049, 1061, 1091, 1151, 1229, 1277, 1289, 1301, 1319, 1427, 1451, 1481, 1487, 1607, 1619, 1667, 1697, 1721, 1787, 1871, 1877
OFFSET
1,1
COMMENTS
Lesser of twin primes without 5.
EXAMPLE
a(1)=3 because 3-1/2-5/2=0(nonprime) and 3-1/2+5/2=5(prime).
MATHEMATICA
Select[Prime[Range[300]], Total[Boole[PrimeQ[#-1/2+{5/2, -5/2}]]]==1&] (* Harvey P. Dale, Jul 14 2019 *)
CROSSREFS
Cf. A001359.
Sequence in context: A126691 A154613 A109654 * A038986 A276848 A194800
KEYWORD
nonn
AUTHOR
EXTENSIONS
Entries checked by R. J. Mathar, May 02 2010
More terms from and definition clarified by Harvey P. Dale, Jul 22 2014
STATUS
approved