%I A090870
%S A090870 2,3,7,69,1642,12073,12073,6496152
%N A090870 a(n) is the smallest m such that d(m+k-1)=2k for k=1,...,n where d(t)= 
               prime(t+1)-prime(t)(differences of consecutive primes in arithmetic 
               progression).
%C A090870 Is this sequence infinite ? a(9) is greater than 105000000.
%F A090870 a[n_] := (For[m=1, !Sum[(d[m+k-1]-2k)^2, {k, n}]==0, m++ ];m)
%e A090870 a(8)=6496152 because prime(6496152)=113575727 and 113575727,
%e A090870 113575729,113575733,113575739,113575747,113575757,
%e A090870 113575769,113575783&113575799 are nine consecutive
%e A090870 primes with differences respectively 2,4,6,8,10,12,14&16.
%t A090870 a[n_] := (For[m=1, !Sum[(d[m+k-1]-2k)^2, {k, n}]==0, m++ ];m); Do[Print[a[n]], 
               {n, 8}]
%Y A090870 Cf. A049232.
%Y A090870 Sequence in context: A087358 A057736 A130309 this_sequence A088542 A075840 
               A096225
%Y A090870 Adjacent sequences: A090867 A090868 A090869 this_sequence A090871 A090872 
               A090873
%K A090870 more,nonn
%O A090870 1,1
%A A090870 Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Dec 11 2003