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 A278230 #13 Nov 22 2016 21:48:41
%S A278230 2,2,2,6,2,8,6,6,2,2,12,12,2,6,6,2,6,6,24,6,12,6,2,2,30,6,12,6,6,2,30,
%T A278230 2,12,12,6,6,60,6,6,2,2,12,2,12,6,30,12,6,30,24,2,2,30,2,6,6,12,6,30,
%U A278230 2,48,2,30,6,30,6,30,72,6,6,6,2,60,12,30,6,6,30,6,60,2,6,2,12,6,2,6,30,6,12,30,6,60,2,24,6,2,6,6,12,30,6,12,6,12,210,12
%N A278230 Least number with the prime signature of 2*prime(n) + 1.
%H A278230 Antti Karttunen, <a href="/A278230/b278230.txt">Table of n, a(n) for n = 1..10000</a>
%F A278230 a(n) = A046523(A072055(n)) = A046523(1 + 2*A000040(n)).
%t A278230 Table[Times @@ MapIndexed[(Prime@ First@ #2)^#1 &, #] &@ If[Length@ # == 1 && #[[1, 1]] == 1, {0}, Reverse@ Sort@ #[[All, -1]]] &@ FactorInteger[ 2 Prime@ n + 1], {n, 120}] (* _Michael De Vlieger_, Nov 21 2016 *)
%o A278230 (Scheme) (define (A278230 n) (A046523 (+ 1 (* 2 (A000040 n)))))
%Y A278230 Cf. A000040, A046523, A072055.
%Y A278230 Cf. A072192 (positions of 2's), A005384.
%Y A278230 Cf. also A278227, A278228, A278229.
%K A278230 nonn
%O A278230 1,1
%A A278230 _Antti Karttunen_, Nov 19 2016