OFFSET
1,1
COMMENTS
Conjecture: There exists no pair of primes (p, q > p^2) such that q - p^2 = 6*n - 4 (see A138479). - Philippe LALLOUET (philip.lallouet(AT)orange.fr), Mar 20 2008
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..5000
FORMULA
a(n) = A046953(n-1) - 1.
EXAMPLE
a(3) = 12 because 6*12 + 5 = 77 is composite.
MATHEMATICA
Select[Range[200], !PrimeQ[6#+5]&] (* Harvey P. Dale, Mar 13 2011 *)
PROG
(PARI) isok(n) = ! isprime(6*n+5); \\ Michel Marcus, Jan 06 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Anton Joha, Jan 26 2001
EXTENSIONS
More terms from Henry Bottomley, Jan 29 2001
STATUS
approved