A272006 - OEIS

%I #28 Sep 01 2016 13:12:56

%S 0,0,0,8,6,2,2,18,6,6,18,2,38,36,30,36,60,2,2,50,38,116,8,116,6,12,66,

%T 102,330,318,56,32,48,60,192,68,66,42,132,2,120,108,62,56,30,8,120,32,

%U 192,8,150,120,326,170,30,20,2,278,158,18,6,92,446,120,56,48,48,48,98,8,32,272,38,78,206

%N a(n) = A003617(n) - A062397(n-1).

%F a(n) = A033873(n-1) - 1. - _Michel Marcus_, Jul 28 2016

%e For n=4, the smallest 4-digit prime is 1009, and 10^(4-1) + 1 = 1001, so a(4) = 1009 - 1001 = 8. - _Michael B. Porter_, Aug 01 2016

%t Table[NextPrime[#] - (# + 1) &[10^(n - 1)], {n, 75}] (* _Michael De Vlieger_, Jul 13 2016 *)

%o (PARI) a(n) = nextprime(10^(n-1)) - (10^(n-1) +  1); \\ _Michel Marcus_, Jul 28 2016

%Y Cf. A003617, A033873, A062397.

%K base,nonn

%O 1,4

%A _Carauleanu Marc_, Jul 13 2016