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 A228541 #19 Jul 06 2024 14:02:18
%S A228541 31,61,62,93,122,124,151,155,181,183,186,211,217,241,244,248,271,279,
%T A228541 302,305,310,331,341,362,366,372,403,421,422,427,434,453,465,482,488,
%U A228541 496,527,541,542,543,549,558,571,589,601,604,610,620,631,633,651,661,662
%N A228541 Numbers having at least one prime factor of the form 30*k + 1.
%C A228541 Together with 2, supersequence of A228556.
%C A228541 Conjecture: Numbers m such that abs(Sum_{k=1..m} [k|m]*A008683(k)*(-1)^(k/15)) = 0. - _Mats Granvik_, Jul 06 2024
%e A228541 183 = 3*61 is in the sequence because 30*2 + 1 is prime.
%e A228541 211 is in the sequence because it is prime and 211 = 30*7 + 1.
%o A228541 (PARI) for(n=31, 662, if(setsearch(Set(factor(n)[, 1]%30), 1)==1, print1(n, ", ")));
%Y A228541 Supersequence of A132230. Cf. A228556.
%K A228541 nonn,less
%O A228541 1,1
%A A228541 _Arkadiusz Wesolowski_, Aug 25 2013