OFFSET
0,3
PROG
(Sage) [power_mod(7, n, 3^n)for n in range(0, 30)] # Zerinvary Lajos, Nov 28 2009
(PARI) a(n) = if (n, lift(Mod(7, 3^n)^n), 0); \\ Michel Marcus, Feb 20 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 20 2008
STATUS
approved