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%I #21 Feb 21 2019 09:20:55
%S 9,93,897,9569,31433,492170,4652430,47326803,436273150,4302407536,
%T 42652618575,738832928197,7177162612050,90874329411895,
%U 218209405436996,1693182318746937,80873624627235459,804212830686678390
%N Smallest nonprime number <= 10^n (n>=1) with maximum distance from a prime.
%C Each number is a mean of two consecutive primes.
%C Since, except 2, primes are odd numbers, this mean is an integer.
%e For n=1: first prime numbers are 2, 3, 5, 7 and 11. Maximum difference between two consecutive primes is 4 between 7 and 11 thus a(1)=9.
%e For n=4: maximum difference between two primes less than 10^4 is 36, which occurs once: between 9551 and 9587. a(4)=(9551 + 9587)/2 = 9569.
%Y Cf. A000040, A001223, A087378, A282690.
%K nonn,more
%O 1,1
%A _David Cobac_, Feb 18 2019
%E More terms (using the b-file at A002386) from _Jon E. Schoenfield_, Feb 19 2019
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