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%I #26 Sep 01 2017 17:43:52
%S 2,2,4,2,16,30,60,30,2,14,16,22,14,36,54,8,10,6,36,90,76,48,40,42,210,
%T 56,176,126,60,42,24,204,188,36,34,56,20,38,34,18,170,106,22,26,112,
%U 416,160,24,60,296,126,64,30,126,136,6,84,10,174,60,286,126,186,6
%N a(n) = difference between the 2 smallest prime numbers > 10^n.
%C (Sum_{n=1..N} a(n)/n)/N appears to tend to log(10) as N increases.
%H Pierre CAMI, <a href="/A227509/b227509.txt">Table of n, a(n) for n = 1..1825</a>
%e 10^1+1=11 is prime as is 13 so a(1)=2.
%e 10^2+1=101 is prime as is 103 so a(2)=2.
%t spn[n_]:=Module[{a=NextPrime[10^n]},NextPrime[a]-a]; Array[spn,70] (* _Harvey P. Dale_, Sep 01 2017 *)
%o PFGW & SCRIPT
%o SCRIPT
%o DIM n,0
%o DIM k
%o DIM g
%o DIMS t
%o OPENFILEOUT myfile,a(n).txt
%o LABEL a
%o SET n,n+1
%o SET k,-1
%o LABEL b
%o SET k,k+2
%o SETS t,%d,%d\,;n;k
%o PRP 10^n+k,t
%o IF ISPRP THEN GOTO c
%o GOTO b
%o LABEL c
%o SET g,k
%o LABEL d
%o SET k,k+2
%o SETS t,%d,%d\,;n;k
%o PRP 10^n+k,t
%o IF ISPRP THEN GOTO e
%o GOTO d
%o LABEL e
%o SET g,k-g
%o SETS t,%d,%d,%d\,;n;g;k
%o WRITE myfile,t
%o GOTO a
%K nonn
%O 1,1
%A _Pierre CAMI_, Jul 14 2013
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