cp's OEIS Frontend

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.

A091340 Amicable numbers with property that each member m of the corresponding amicable pair is divisible by sopfr(m) (the sum of prime factors with repetition, A001414).

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%I A091340 #48 Jul 15 2022 06:34:28
%S A091340 821921625,988676775,4024942087978,4179223134422,100733767393275,
%T A091340 110452715806725
%N A091340 Amicable numbers with property that each member m of the corresponding amicable pair is divisible by sopfr(m) (the sum of prime factors with repetition, A001414).
%C A091340 Both members of the amicable pair appear in the sequence.
%C A091340 Conjecture: sequence is finite (even though there are many known amicable numbers - about 8*10^7 currently).
%C A091340 _Sergei Chernykh_ and the teams @Boinc found a new pair with their still ongoing search in the 21-digit range, 109297847965212832096 with sopfr(m)=118618 and 109392896505354817184 with sopfr(m)=39152. - _Sven Simon_, Sep 19 2020
%H A091340 Sergei Chernykh, <a href="http://sech.me/ap/index.html">Amicable pairs list</a>
%H A091340 J. O. M. Pedersen, <a href="http://amicable.homepage.dk/tables.htm">Tables of Aliquot Cycles</a> [Broken link]
%H A091340 J. O. M. Pedersen, <a href="http://web.archive.org/web/20140502102524/http://amicable.homepage.dk/tables.htm">Tables of Aliquot Cycles</a> [Via Internet Archive Wayback-Machine]
%H A091340 J. O. M. Pedersen, <a href="/A063990/a063990.pdf">Tables of Aliquot Cycles</a> [Cached copy, pdf file only]
%e A091340 a(1): 821921625 = 3^2*5^3*7*29*59*61, sopfr(n) = 177 = 3*59.
%e A091340 a(2): 988676775 = 3^2*5^2*71*199*311, sopfr(n) = 597 = 3*199.
%Y A091340 Cf. A001414, A046346, A063990, A259180 (amicable pairs).
%Y A091340 Cf. A267076 (amicable pairs that have the same sopfr).
%K A091340 nonn,more
%O A091340 1,1
%A A091340 _Sven Simon_, Dec 31 2003