A082493 - OEIS

%I #17 Aug 24 2023 10:36:05

%S 0,0,1,0,3,2,5,0,1,6,9,8,11,10,7,0,15,8,17,4,13,18,21,8,18,22,1,12,27,

%T 26,29,0,25,30,17,8,35,34,31,24,39,20,41,28,28,42,45,32,19,26,43,36,

%U 51,26,12,24,49,54,57,44,59,58,55,0,33,2,65,52,61,26,69,8,71,70,7,60,59,14

%N a(n) = n*ceiling(2^n/n) - 2^n.

%C Least nonnegative k such that (2^n+k)/n is an integer.

%C If n is a power of 2, a(n) = 0; otherwise a(n) = n - A015910(n). - _Robert Israel_, Apr 08 2015

%H Robert Israel, <a href="/A082493/b082493.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = -(2^n) mod n. - _Robert Israel_, Apr 08 2015

%p seq(-2&^n mod n, n = 1 .. 100); # _Robert Israel_, Apr 08 2015

%o (Python)

%o def A082493(n): return (-pow(2,n,n))%n # _Chai Wah Wu_, Aug 24 2023

%Y Cf. A053638, A015910, A000799, A082494, A215747.

%K easy,nonn,look

%O 1,5

%A _Vladeta Jovovic_, Apr 28 2003