A077815 2^phi(n) mod n^2, where phi is Euler's totient function A000010.

0, 2, 4, 4, 16, 4, 15, 16, 64, 16, 56, 16, 40, 64, 31, 0, 222, 64, 58, 256, 127, 56, 392, 256, 451, 40, 433, 176, 30, 256, 187, 0, 958, 800, 841, 208, 38, 780, 586, 1536, 944, 568, 1076, 1200, 91, 392, 2069, 1024, 2157, 1076, 1021, 1600, 1909, 2620, 826, 2752

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(42) = 2^phi(42) mod 42*42 = 2^phi(2*3*7) mod 1764 = 2^(42*(1-1/2)*(1-1/3)*(1-1/7)) mod 1764 = 2^12 mod 1764 = 4096 mod 1764 = 568.

Mathematica

PowerMod[2, EulerPhi[#], #^2]&/@Range[60] (* Harvey P. Dale, Dec 04 2021 *)

Prog

(PARI) a(n)=lift(Mod(2, n^2)^eulerphi(n)) \\ Charles R Greathouse IV, Feb 21 2013

Crossrefs

Cf. A077816, A000010, A000290.

Sequence in context: A221706 A368585 A145891 * A218075 A366709 A064449

Adjacent sequences: A077812 A077813 A077814 * A077816 A077817 A077818

Keyword

nonn

Author

Reinhard Zumkeller, Nov 17 2002

Status

approved