This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A139326 #3 Mar 30 2012 18:51:00
%S A139326 0,1,2,2,2,2,2,2,2,3,2,4,3,4,4,4,3,3,4,5,4,6,5,5,5,5,5,5,4,5,5,5,6,6,
%T A139326 5,5,5,8,6,7,7,8,7,7,8,8,8,9,9,8,9,9,10,10,9,9,8,9,9,9,10,10,11,9,11,
%U A139326 10,11,10,11,11,11,12,12,12,13,12,13,13,13,12,13,14,15,14,12,13,13,15,14
%N A139326 Write the first n^2 odd numbers consecutively in n rows of length n: a(n) = minimal number of primes in a row.
%C A139326 a(n) = Min{A139325(n,k): 1<=k<=n}.
%e A139326 a(4)=Min{#{3,5,7},#{11,13},#{17,19,23},#{29,31}}=Min{3,2,3,2}=2:
%e A139326 ..1 ...3 ...5 ...7 ... primes in first row = {3,5,7},
%e A139326 ..9 ..11 ..13 ..15 ... primes in 2nd row = {11,13},
%e A139326 .17 ..19 ..21 ..23 ... primes in 3rd row = {17,19},
%e A139326 .25 ..27 ..29 ..31 ... primes in 4th row = {29,31}.
%Y A139326 Cf. A139327, A083382.
%K A139326 nonn
%O A139326 1,3
%A A139326 _Reinhard Zumkeller_, Apr 14 2008