A066602 a(n) = 4^n mod n.

0, 0, 1, 0, 4, 4, 4, 0, 1, 6, 4, 4, 4, 2, 4, 0, 4, 10, 4, 16, 1, 16, 4, 16, 24, 16, 1, 4, 4, 16, 4, 0, 31, 16, 9, 28, 4, 16, 25, 16, 4, 22, 4, 36, 19, 16, 4, 16, 18, 26, 13, 48, 4, 28, 34, 16, 7, 16, 4, 16, 4, 16, 1, 0, 49, 4, 4, 52, 64, 46, 4, 64, 4, 16, 49

Offset: 1

Author

Amarnath Murthy, Dec 22 2001

Keywords

• base
• easy
• nonn

Examples

			a(7) = 4 as 4^7 = 16384 = 7*2340 + 4.
		

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Programs

Maple

seq(irem(4^n,n),n=1..75); # Zerinvary Lajos, Apr 20 2008

Mathematica

Table[PowerMod[4, i, i], {i, 50}]

PARI

a(n) = { lift(Mod(4,n)^n) } \\ Harry J. Smith, Mar 09 2010

Extensions

More terms from Harvey P. Dale and Robert G. Wilson v, Dec 23 2001