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 A101938 #9 May 16 2017 04:30:44 %S A101938 37,53,64,67,89,97,113,121,131,157,163,173,211,223,233,251,263,277, %T A101938 289,293,307,317,331,337,343,353,367,373,379,383,389,397,401,409,439, %U A101938 443,449,457,467,479,487,491,499,503,509,512,529,541,547 %N A101938 Numbers n with omega(n) < omega of 2 nearest larger and 2 nearest smaller neighbors. %H A101938 G. C. Greubel, <a href="/A101938/b101938.txt">Table of n, a(n) for n = 1..10000</a> %e A101938 173 is in the sequence because it has one unique prime factor (itself), whereas %e A101938 171, 172, 174 and 175 each have more. %t A101938 For[i=2, i<1000, If[And[Length[FactorInteger[i-2]]>Length[FactorInteger[i]], Length[FactorInteger[i-1]]>Length[FactorInteger[i]], Length[FactorInteger[i+1]]>Length[FactorInteger[i]], Length[FactorInteger[i+2]]>Length[FactorInteger[i]]], Print[i]];i++ ] %t A101938 Select[Range[6500], PrimeNu[#] < Min[PrimeNu[# - 1], PrimeNu[# - 2], PrimeNu[# + 1], PrimeNu[# + 2]] &] (* _G. C. Greubel_, May 15 2017 *) %Y A101938 Cf. A001221, A101934. %K A101938 easy,nonn %O A101938 1,1 %A A101938 _Neil Fernandez_, Dec 21 2004