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 A275470 #15 Aug 06 2016 14:21:37 %S A275470 32,13,152,272,68,56,1155,560,32,2025,6532,9009,4490,11835,392,8775, %T A275470 5756,13210,2240,2288,9032,2860,42272,40652,55426,21592,8944,8575, %U A275470 5840,1755,34648,38072,4664,33536,38296,57796,35296,30555,10856,41384 %N A275470 Half the difference between the larger and smaller terms of the n-th amicable pair (x,y) given in A259933. %C A275470 Each term represents the radius of an interval (x,y), where x (A260086) and y (A260087) form a pair of amicable numbers (A259933). The midpoint and length of each interval can be found in A275316 and A275469, respectively. %C A275470 A term will be odd if and only if y-x = 2 mod 4. This occurs when x and y have the same parity but their average has the opposite parity. %C A275470 This sequence is a rearrangement of A162884 (which is based on A002025, A002046, and A066539). The first ten indices for which a(n) does not equal A162884(n) are n = 9, 10, 11, 15, 16, 33, 34, 35, 41, 42. %H A275470 Timothy L. Tiffin, <a href="/A275470/b275470.txt">Table of n, a(n) for n = 1..142</a> %H A275470 VaxaSoftware, <a href="http://www.vaxasoftware.com/doc_eduen/mat/numamigos_eng.pdf">List of amicable numbers from 1 to 20,000,000</a> [142 pairs]. %F A275470 a(n) = [A260087(n) - A260086(n)]/2 = A275469(n)/2. %e A275470 a(1) = (284-220)/2 = 64/2 = 32, a(2) = (1210-1184)/2 = 26/2 = 13, and a(3) = (2924-2620)/2 = 304/2 = 152. %Y A275470 Cf. A002025, A002046, A066539, A260086, A260087, A162884, A259933, A275316, A275469. %K A275470 nonn %O A275470 1,1 %A A275470 _Timothy L. Tiffin_, Jul 28 2016