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 A048741 #12 Sep 07 2019 08:49:25 %S A048741 2,6,8,3,10,144,14,15,64,324,400,21,22,13824,5,26,27,784,27000,1024, %T A048741 33,34,35,279936,38,39,64000,74088,1936,2025,46,5308416,7,2500,51, %U A048741 2704,157464,55,175616,57,58,777600000,62,3969,32768,65,287496,4624,69 %N A048741 Product of aliquot divisors of composite n (1 and primes omitted). %D A048741 Albert H. Beiler, Recreations in the Theory of Numbers, 2nd ed., pages 10, 23. New York: Dover, 1966. ISBN 0-486-21096-0. %H A048741 Amiram Eldar, <a href="/A048741/b048741.txt">Table of n, a(n) for n = 1..10000</a> %F A048741 a(n) = A007956(A002808(n)). - _Michel Marcus_, Sep 07 2019 %e A048741 The third composite number is 8, for which the product of aliquot divisors is 4*2*1 = 8, so a(3)=8. %t A048741 Composite[n_] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; Table[ Times @@ Select[ Divisors[ Composite[n]], # < Composite[n] & ], {n, 1, 60} ] %t A048741 pd[n_] := n^(DivisorSigma[0, n]/2 - 1); pd /@ Select[Range[100], CompositeQ] (* _Amiram Eldar_, Sep 07 2019 *) %Y A048741 This is A007956 omitting the 1's. %Y A048741 Cf. A002808, A007422, A007956, A048740. %K A048741 easy,nonn %O A048741 1,1 %A A048741 _Enoch Haga_ %E A048741 a(33) inserted by _Amiram Eldar_, Sep 07 2019