OFFSET
0,2
LINKS
FORMULA
MATHEMATICA
LinearRecurrence[{1, 6}, {-1, 17}, 26] (* James C. McMahon, Jan 30 2024 *)
PROG
(Python)
def A369490(n): return 3**(n+1)+(1<<n+2 if n&1 else -(1<<n+2)) # Chai Wah Wu, Feb 25 2024
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Philippe Deléham, Jan 24 2024
STATUS
approved