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 A255412 #11 Apr 14 2015 10:26:47 %S A255412 4800,28800,57600,67200,86400,96000,115200,148800,144000,142800, %T A255412 153600,182400,201600,211200,230400,259200,345600,288000,297600, %U A255412 403200,326400,345600,355200,384000,403200,518400,432000,576000,470400,489600,499200,518400,528000,547200,691200,638400,748800,614400,633600,662400,672000,806400,864000,856800,720000 %N A255412 a(n) = A000203(A255334(n)). %C A255412 Sequence gives value of sigma(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 by the magnitude of n, and contains duplicates, because there are cases of multiple such pairs having the same value of sigma. %C A255412 The first such duplicate values occur as a(17) = a(22) = 345600 and a(20) = a(25) = 403200. %H A255412 Antti Karttunen, <a href="/A255412/b255412.txt">Table of n, a(n) for n = 1..6589</a> %F A255412 a(n) = A000203(A255334(n)). %F A255412 a(n) = A000203(A255423(n)). %o A255412 (Scheme) (define (A255412 n) (A000203 (A255334 n))) %Y A255412 Cf. A254035 (same sequence sorted into ascending order, with duplicates removed). %Y A255412 Cf. A000203, A007947, A255334, A255423, A255424. %K A255412 nonn %O A255412 1,1 %A A255412 _Antti Karttunen_, Apr 05 2015