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 A101294 #11 May 16 2017 04:30:35 %S A101294 56,93,94,117,143,144,145,146,160,207,214,215,216,217,297,303,325,326, %T A101294 327,393,537,687,723,801,1137,1347,1467,1537,1713,1943,1983,2103,2217, %U A101294 2304,2305,2306,2427,2643,2666,2716,3867,3914,4413 %N A101294 Numbers n such that omega(n-2) = omega(n-1) = omega(n) = omega(n+1) = omega(n+2). %H A101294 G. C. Greubel, <a href="/A101294/b101294.txt">Table of n, a(n) for n = 1..5000</a> %e A101294 143 is in the sequence because it has two unique prime factors (11 and 13), the same number as its two nearest neighbors on both sides (141 has 3 and 47, 142 has 2 and 71, 144 has 2 and 3 and 145 has 5 and 29). %t A101294 For[i=2, i<10000, 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 A101294 Select[Range[600000], PrimeNu[# - 2] == PrimeNu[# - 1] == PrimeNu[#] == PrimeNu[# + 1] == PrimeNu[# + 2] &] (* _G. C. Greubel_, May 15 2017 *) %Y A101294 Cf. A001221, A101932. %K A101294 easy,nonn %O A101294 1,1 %A A101294 _Neil Fernandez_, Dec 21 2004 %E A101294 Edited by _N. J. A. Sloane_, Mar 17 2007