OFFSET
0,1
COMMENTS
For n >= 3, a(n) is not of the form 2^k + p, where p is a prime. Therefore every term greater than 11 is in A006285 (de Polignac numbers).
LINKS
Wacław Sierpiński, Elementary Theory of Numbers, Monografie Matematyczne 42 (1964), p. 415.
FORMULA
a(n) = A000215(n) - 6.
a(0) = - 3; a(n) = (a(n-1) + 5)^2 - 5, n >= 1.
MATHEMATICA
Table[2^(2^n) - 5, {n, 0, 8}]
PROG
(Magma) [2^(2^n)-5 : n in [0..8]]
(PARI) for(n=0, 8, print1(2^(2^n)-5, ", "));
(Python)
def A232460(n): return (1<<(1<<n))-5 # Chai Wah Wu, Jul 19 2022
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Arkadiusz Wesolowski, Nov 24 2013
STATUS
approved