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 A076690 #2 Feb 11 2014 19:05:32 %S A076690 2,3,2,5,3,7,2,3,4,11,3,13,5,4,2,17,3,19,4,5,7,23,3,5,8,3,5,29,4,31,2, %T A076690 7,10,6,3,37,11,8,4,41,5,43,7,4,13,47,3,7,4,10,8,53,3,8,5,11,16,59,4, %U A076690 61,17,5,2,9,7,67,10,13,5,71,3,73,20,4,11,9,8,79,4,3,22,83,5,11,23,16 %N A076690 Nearest integer to average of the smallest and largest prime factors of n (0.5 is rounded to 1). %e A076690 The smallest and largest prime factors of 6 are 2 and 3, respectively, the average of which is 2.5, rounding off to 3. Hence a(6) = 3. %t A076690 f[n_] := Module[{p, l}, p = Transpose[FactorInteger[n]][[1]]; l = Length[p]; Ceiling[(p[[1]] + p[[l]])/2]]; Table[f[i], {i, 2, 100}] %K A076690 easy,nonn %O A076690 2,1 %A A076690 _Joseph L. Pe_, Oct 25 2002