%I #5 Aug 13 2014 22:57:43

%S 1,1,1,-3,7,3,3,-9,7,7,19,3,-11,-29,-27,-11,61,-3,3,-39,-11,-101,9,

%T -23,7,13,67,-99,-209,-27,-11,-27,-21,-9,193,-23,67,43,-59,3,-17,109,

%U 63,57,31,-9,-33,33,-33,9,-57,121,-231,171,31,21,3,-93,-149,19,7,-39,-83,121,-51,49,49,49,99,9,33,-53,39,79,-47,129,133

%N Integer k such that 10^n + k = A115062(n).

%C For terms after the first several, 10^n + a(n) is only known to be a highly probable prime. If, for m>0, 10^n - m and 10^n + m are both nearest primes to 10^n, a(n) = -m. For example, a(17) = -3 as 10^17-3 and 10^17+3 are the nearest primes to 10^17. Similarly, a(45) = -9 with both 10^45-9 and 10^45+9 prime.

%F a(n) = A115062(n) - 10^n.

%e a(4) = 7 as 10^4 + 7 = 10007 = A115062(4), the nearest prime to 10^4.

%p a:= n-> (t->((p, q)->`if`(q-t<t-p, q, p)-t)(`if`(t=1, -1,

%p prevprime(t)), nextprime(t)))(10^n):

%p seq(a(n), n=0..80); # _Alois P. Heinz_, Aug 13 2014

%Y Cf. A115062.

%K sign

%O 0,4

%A _Rick L. Shepherd_, Mar 02 2006