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 A278247 #9 Nov 22 2016 21:49:37 %S A278247 1,2,2,2,2,2,6,2,2,2,2,6,2,6,2,2,6,6,2,2,2,6,6,2,6,2,6,2,6,2,2,6,6,6, %T A278247 2,8,6,2,2,6,2,12,6,2,2,2,30,2,6,2,6,30,2,2,2,2,6,6,2,2,6,30,6,2,2,2, %U A278247 6,2,6,2,6,6,6,6,6,2,6,6,6,30,6,6,2,12,2,2,6,6,2,6,6,30,2,2,6,2,6,6,6,2,2,30,2,6,6,6,6,6,6,6,6,6,6,2,2,6,30,6,6 %N A278247 a(n) = least number with the same prime signature as n + (n+1)^2. %C A278247 Almost all terms seem to be primorials, 4848 of the first 5000, in other words, most terms of A028387 (in the same range) are squarefree. %H A278247 Antti Karttunen, <a href="/A278247/b278247.txt">Table of n, a(n) for n = 0..5000</a> %F A278247 a(n) = A046523(A028387(n)). %o A278247 (Scheme) (define (A278247 n) (A046523 (A028387 n))) %Y A278247 Cf. A028387, A046523. %Y A278247 Cf. also A278246, A278251, A278253, A278255. %K A278247 nonn %O A278247 0,2 %A A278247 _Antti Karttunen_, Nov 21 2016