%I #4 Mar 30 2012 17:39:08
%S 1,2,11,20,83,149,188,209,326,347,566,944,1301,1565,1574,1607,1805,
%T 1892,1943,2102,2228,2531,3173,3485,4379,5135,5534,6299,6722,6950,
%U 7223,7727,7970,8105,8273,8882,9785,9914,10112,10985,11654,11930,12221,13547
%N Positions of 4 in A038800.
%C Starting with a(2)=2, numbers m such that 10(m-1)+{1,3,7,9} are all primes.
%C Essentially the same as A064975. [From _R. J. Mathar_, Aug 11 2008]
%D 4 is maximal possible number of primes between 10n and 10(n+1).
%e 11 is OK because 10(11-1)+{1,3,7,9} = 101,103,107,109 all prime.
%Y Cf. A038800 Number of primes between 10n and 10n+9.
%Y Cf. A038800.
%K nonn
%O 1,2
%A _Zak Seidov_, Mar 01 2006