OFFSET
1,1
COMMENTS
a(6) and a(7) have 427 and 1773 digits, respectively, and are thus too large to include.
EXAMPLE
a(1)=5 (=3*2^3-2*3^2-1), a(2)=131 (=4*3^4-3*4^3-1), a(3)=54869 (=6*5^6-5*6^5-1), a(4)=863585783 (=9*8^9-8*9^8-1).
MATHEMATICA
Select[Table[n(n-1)^n-(n-1)n^(n-1)-1, {n, 200}], PrimeQ] (* Harvey P. Dale, Jun 19 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jun 12 2011
STATUS
approved