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 A172155 #7 Jul 16 2020 19:52:15
%S A172155 1,1,1,2,1,2,1,2,2,1,2,1,2,2,2,2,1,1,2,4,3,2,1,4,1,2,2,2,3,1,4,1,1,4,
%T A172155 2,4,2,1,2,1,6,2,2,2,1,3,1,4,2,4,2,1,2,6,2,2,6,1,2,2,2,2,2,3,2,2,2,2,
%U A172155 4,1,6,1,2,2,2,3,1,2,6,2,2,2,2,2,2,4,1,4,4,3,2,4,2,2,1,3,4,2,3,1,3,2,1,8,2
%N A172155 a(n) = Omega(6*n-1)*Omega(6*n+1).
%e A172155 For n=1, Omega(6*n-1)*Omega(6*n+1)=Omega(5)*Omega(7)=1, so a(1)=1.
%p A172155 A172155 := proc(n) numtheory[bigomega](6*n-1)*numtheory[bigomega](6*n+1) ; end proc: seq(A172155(n),n=1..100) ; # _R. J. Mathar_, Jan 30 2010
%t A172155 Table[Times@@PrimeOmega[6*n+{1,-1}],{n,120}] (* _Harvey P. Dale_, Jul 16 2020 *)
%Y A172155 Cf. A145193.
%K A172155 nonn
%O A172155 1,4
%A A172155 _Juri-Stepan Gerasimov_, Jan 26 2010
%E A172155 Corrected by _R. J. Mathar_, Jan 30 2010