OFFSET
2,1
COMMENTS
No solution for n = 1, so sequence starts at n = 2.
The primes are probable primes for n > 23.
FORMULA
a(n) = 6^n + A233546(n).
EXAMPLE
a(2) = 6^2 + A233546(2) = 36 + 11 = 47.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Sondow, Dec 16 2013
STATUS
approved