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 A034898 #27 Feb 16 2025 08:32:37 %S A034898 1,2,1,6,3,1,12,18,18,12,2,30,1,11,6,2,60,48,19,132,132,10,192,2,31, %T A034898 168,108,66,35,252,78,132,342,366,390,168,348,282,498,540,546,59,12, %U A034898 378,438,4,222,336,18,660,138,798,810,528,450,75,252,150,948,162 %N A034898 n-th term of A034897 is an a(n)-hyperperfect number. %D A034898 R. K. Guy, Unsolved Problems in Number Theory, Sect. B2. %D A034898 Roberts, Lure of the Integers, see Integer 28, p. 177. %H A034898 Donovan Johnson, <a href="/A034898/b034898.txt">Table of n, a(n) for n = 1..10000</a> %H A034898 Judson S. McCranie, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL3/mccranie.html">A Study of Hyperperfect Numbers</a>, Journal of Integer Sequences, Vol. 3 (2000), Article 00.1.3. %H A034898 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HyperperfectNumber.html">Hyperperfect Number.</a> %o A034898 (PARI) forcomposite(n=2, 10^8, if(1==Mod(n, sigma(n)-n-1), print1((n-1)/(sigma(n)-n-1)", "))) \\ _Hans Loeblich_, May 10 2019 %Y A034898 Cf. A034897. %K A034898 nonn %O A034898 1,2 %A A034898 _Jud McCranie_ %E A034898 More terms from _Donovan Johnson_, Nov 20 2012