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 A109928 #6 Jul 15 2018 13:06:55
%S A109928 1,2,4,13,6,10,20,47,22,18,28,34,51,40,62,36,30,50,48,74,42,82,80,54,
%T A109928 105,72,60,147,78,66,116,134,84,96,142,146,108,90,114,102,172,206,130,
%U A109928 160,226,120,144,138,126,196,248,262,162,170,302,156,186,274,356,174
%N A109928 Least k such that there are n primes of the form kr+1 with 1<=r<=k. Index of the first occurrence of n in A085053.
%e A109928 a(6) = 10 as 10 is the least number that gives 6 primes of the form 10k +1, k<=10. (11,31,41,61,71,101).
%t A109928 t=Table[Length[Select[Range[n], PrimeQ[n#+1]&]], {n, 1000}]; Table[First[Flatten[Position[t, n]]], {n, 100}] (Noe)
%Y A109928 Cf. A085053 (number of primes of the form kn+1, with k<=n).
%K A109928 nonn
%O A109928 1,2
%A A109928 _Amarnath Murthy_, Jul 17 2005
%E A109928 More terms from _T. D. Noe_, Jul 17 2005