OFFSET
1,2
COMMENTS
No terms end with 2, 3, 7, 8. Minimal differences are 1; e,g., a(52) - a(51) = 1715 - 1714. There are no three consecutive terms with common difference 1.
Distribution of last digits for first 61000 terms: W(0..9) = (10190, 10162, 0, 0, 10178, 10222, 10027, 0, 0, 10221).
For "existing" digits distribution is rather uniform.
LINKS
Jens Kruse Andersen, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = (1/6)*A245591(n+1)^(1/3).
EXAMPLE
m = 1: (6m)^3 = 216 = 107 + 109, m = 29: (6m)^3 = 5268024 = 2634011 + 2634013.
MAPLE
select(n -> isprime(108 * n^3 - 1) and isprime(108 * n^3 + 1), [$1..1000]); # Robert Israel, Aug 03 2014
MATHEMATICA
Select[Range[1000], PrimeQ[216#^3/2 - 1] && PrimeQ[216#^3/2 + 1] &] (* Alonso del Arte, Aug 02 2014 *)
PROG
(PARI) N=2*10^3; for(k=1, N, p=216*k^3; if(isprime(p/2-1)&&isprime(1+p/2), print1(k, ", ")))
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Aug 02 2014
STATUS
approved