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 A255424 #7 Apr 14 2015 10:27:03 %S A255424 42,210,462,546,714,798,966,210,1218,78,1302,1554,1722,1806,1974,2226, %T A255424 2310,2478,2562,2730,2814,2982,3066,3318,3486,3570,3738,3990,4074, %U A255424 4242,4326,4494,4578,4746,4830,462,210,5334,5502,5754,5838,6006,6090,390,6258,6342,6510,6594,6846,7014,546,7266,7518,7602,7770,7854,8022,8106,8274,8358,8610 %N A255424 Squarefree kernel of A255334: a(n) = A007947(A255334(n)). %C A255424 Sequence gives value of A007947(n) for numbers n for which there exists k > n such that A000203(k) = A000203(n) and A007947(k) = A007947(n), where A000203 gives the sum of divisors, and A007947 gives the squarefree kernel of n. The sequence is ordered according to the magnitude of n, and contains duplicates, because there are cases of multiple such pairs having same squarefree kernel. %C A255424 The first duplicate occurs as a(2) = a(8) = 210. %H A255424 Antti Karttunen, <a href="/A255424/b255424.txt">Table of n, a(n) for n = 1..6589</a> %F A255424 a(n) = A007947(A255334(n)). %F A255424 a(n) = A007947(A255423(n)). [Equally, squarefree kernel of A255423(n).] %o A255424 (Scheme) (define (A255424 n) (A007947 (A255334 n))) %Y A255424 Cf. A007947, A255334, A255412, A255423, A255425, A255426. %K A255424 nonn %O A255424 1,1 %A A255424 _Antti Karttunen_, Apr 06 2015