OFFSET
1,1
COMMENTS
Both can't be the same form 3n+1 or 3n+2. Since the primes alternate very frequently between 3n+1, 3n+2, 3n+1... this sequence produces a decent frequency of primes.
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
For 19 and 23, 23*10 - 19 = 230-19 = 211, a prime.
MAPLE
R:= NULL: q:= 2: count:= 0:
while count < 100 do
p:= q; q:= nextprime(q);
if isprime(10*q-p) then count:= count+1; R:= R, p fi
od:
R; # Robert Israel, Jul 14 2020
MATHEMATICA
a = {}; For[n=1, n<200, n++, If[PrimeQ[10*Prime[n+1]-Prime[n]], AppendTo[a, Prime[n]]]]; a (* Stefan Steinerberger, Jun 07 2007 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot, Jun 04 2007
EXTENSIONS
Corrected and extended by Stefan Steinerberger, Jun 07 2007
STATUS
approved