OFFSET
1,4
COMMENTS
a(8) has 247 digits.
a(9) has 1976 digits. - Harvey P. Dale, Feb 11 2024
EXAMPLE
For n = 5: a(5) = (-2)^(5-1) - 1 = 15.
MATHEMATICA
nxt[{n_, a_}]:={n+1, a^n-1}; NestList[nxt, {1, 1}, 7][[;; , 2]] (* Harvey P. Dale, Feb 11 2024 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Jaroslav Krizek, Nov 03 2010
STATUS
approved