A066608 a(n) = 4^n mod n^4.

0, 0, 64, 0, 399, 208, 1978, 0, 6265, 8576, 6978, 1792, 19075, 22864, 36199, 0, 17089, 87616, 31867, 107776, 83791, 142928, 195688, 225280, 201999, 302656, 362152, 304896, 401393, 546976, 612688, 0, 226279, 629152, 399674, 718336, 1132463

Offset: 1

Author

Amarnath Murthy, Dec 22 2001

Keywords

• easy
• nonn

Examples

			a(7) = 1978 as 4^7 = 16384 = (7^4)*6 + 1978.
		

Links

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

Crossrefs

Cf. A066606.

Programs

Mathematica

Table[PowerMod[4,n,n^4],{n,50}] (* Harvey P. Dale, Aug 25 2023 *)

PARI

a(n) = { lift(Mod(4, n^4)^n) } \\ Harry J. Smith, Mar 11 2010

Extensions

More terms from Floor van Lamoen and Robert G. Wilson v, Dec 23 2001