OFFSET
1,2
COMMENTS
Next term a(5) has 783 decimal digits.
Conjecture of Kenneth J Ramsey from May 16 2006 (see A001109): a(n) is divisible by 2^prime(n)-1 if and only 2^prime(n)-1 is a Mersenne prime.
MATHEMATICA
Table[Expand[((2*Sqrt[2] + 3)^(2^(Prime[n] - 1) - 1) - (3 - 2*Sqrt[2])^(2^(Prime[n] - 1) - 1))/(4*Sqrt[2])], {n, 1, 10}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Apr 22 2008
STATUS
approved