%I
%S 2,211,211151,2111011129,211101100910009,211101100910007100049,
%T 2111011009100071000031000453,211101100910007100003100000310000721,
%U 211101100910007100003100000310000019100000543,2111011009100071000031000003100000191000000071000000531
%N Smallest prime whose decimal expansion consists of the concatenation of a 1digit prime, a 2digit prime, a 3digit prime, ..., and an ndigit prime.
%C It is a plausible conjecture that a(n) always exists.
%C a(n) has A000217(n) = n*(n+1)/2 digits.
%e a(4) = 2111011129, the smallest prime formed from a singledigit, a doubledigit, a tripledigit, and a quadrupledigit prime, i.e., 2, 11, 101, 1129.
%Y Cf. A000040, A000217, A003617.
%Y Subsequence of A195302.
%Y Cf. A338968 (similar with largest prime).
%K nonn,base
%O 1,1
%A _Jonathan Vos Post_, Aug 18 2012
%E Edited by _N. J. A. Sloane_, Aug 18 2012
