A138654 7^n mod 4^n.

0, 3, 1, 23, 97, 423, 2961, 4343, 63169, 245575, 408305, 1809559, 84001, 50919655, 155110993, 548906039, 2768600449, 15085235847, 36877174193, 258140219351, 707469907681, 2753266098215, 10476769665297, 20560829523831, 73557062489153, 233424460713415

Offset: 0

Author

N. J. A. Sloane, May 20 2008

Keywords

• nonn

Programs

Mathematica

Table[PowerMod[7,n,4^n],{n,0,30}] (* Harvey P. Dale, Aug 26 2019 *)